bluuebunny/crossref_metadata_2025 huggingface dataset:
Bioavailability of methionine hydroxy analog‐free acid relative to DL‐methionine in broilers
Authors: PAYNE Robert L. , LEMME Andreas , SEKO Hiroaki , HASHIMOTO Yasushi , FUJISAKI Hirokazu , KORELESKI Jerzy , SWIATKIEWICZ Sylwester , SZCZUREK Witold , ROSTAGNO Horatio
Published: August 2006

Three experiments were conducted to determine and validate the relative bioefficacy of the liquid form of hydroxy analog (liquid MHA‐FA) to that of DL‐methionine (Met) in male broilers. In experiments 1 and 2, 945 and 550 male broilers were fed either a Met‐deficient basal diet, or the basal diet supplemented with four and five equimolar levels of each Met source, respectively. In experiment 3, 1232 male broilers were fed either a Met‐deficient basal diet, or the basal diet with three levels (low, moderate, or high) of liquid MHA‐FA or DL‐Met at 65% of the liquid MHA‐FA level. Growth performance improved in all trials, regardless of the Met source, relative to those broilers fed the basal diet. In experiments 1 and 2, the bioefficacy estimates for liquid MHA‐FA relative to DL‐Met on a product basis were: 50% and 64% for weight gain, 51% and 59% for the feed conversion ratio, and 54% and 48% for breast‐meat yield, respectively. In experiment 3, there were no differences between the DL‐Met or liquid MHA‐FA treatments, and the broilers fed liquid MHA‐FA were 68% as efficient on a product basis as those fed DL‐methionine for weight gain. The results from these three trials indicate that the bioefficacy of liquid MHA‐FA relative to DL‐methionine is 57% on a product basis on average across all criteria tested.
Effect of propionate, pyruvate and β‐hydroxybutyric acid on pyruvate carboxylase mRNA expression of in vitro culture bovine hepatocytes
Authors: XU Chuang , WANG Zhe
Published: August 2006

The objective was to detect the effect of propionate, pyruvate and β‐hydroxybutyric acid on pyruvate carboxylase mRNA expression in in vitro culture bovine hepatocytes through a quantity reverse transcription polymerase chain reaction method. Pyruvate carboxylase is a key enzyme in the liver gluconeogenesis of ruminants and plays an important role in the negative energy balance of peri‐parturient dairy cows. The effect of propionate, pyruvate and β‐hydroxybutyric acid on pyruvate carboxylase mRNA expression at cell level is presented in this article. In experiment 1, the various concentrations of propionate from 0 mmol/L to 11.5 mmol/L, were added to the hepatocytes media. The results indicate that the level of pyruvate carboxylase mRNA was significantly enhanced accompanying increased propionate concentrations in the media (P < 0.01) and high concentrations of propionate did not inhibit the levels of pyruvate carboxylase mRNA. In experiment 2, pyruvate in concentrations from 0 mmol/L to 12 mmol/L was added to the media. The results indicate that the levels of pyruvate carboxylase mRNA were significantly enhanced when concentrations of pyruvate increased from 0 mmol/M to 4 mmol/M and decreased when concentrations of pyruvate increased from 8 mmol/M to 12 mmol/M (P < 0.01). In experiment 3, β‐hydroxybutyric acid of various concentrations from 0 mmol/L to 3.0 mmol/L was added to the media. The results indicate that pyruvate carboxylase mRNA levels increased slightly when concentrations of β‐hydroxybutyric acid were less than 1 mmol/L, and pyruvate carboxylase mRNA levels decreased significantly when they exceeded 2 mmol/L or 3 mmol/L (P < 0.01). There results suggest that β‐hydroxybutyric acid inhibits PC mRNA expression.
Plasma Lipoprotein Abnormalities in Hemodialysis Patients—Clinical Implications and Therapeutic Guidelines
Authors: Shoji Tetsuo , Nishizawa Yoshiki
Published: August 2006

Abstract:  Patients with advanced stages of chronic kidney disease (CKD) have an increased risk of death from cardiovascular disease (CVD). Dyslipidemias are associated with atherosclerotic vascular changes and the risk of occurrence of acute myocardial infarction in hemodialysis patients. However, management of dyslipidemia in hemodialysis patients does not appear to be actively carried out in routine practice. Presumably, there are three reasons for this reluctance to lipid‐lowering in hemodialysis patients. First, there are epidemiological data showing the inverse relationship between cholesterol and mortality rate; a high cholesterol predicts a better survival. Second, lipids are not usually measured using standard fasting serum, but a non‐fasting specimen. Third, although hypertriglyceridemia is the most common abnormality, fibrates are contraindicated in patients with renal failure because of a high risk of rhabdomyolysis. These issues are discussed in the current review article. Based on published work, lipid lowering would not increase the death rate if carried out without worsening malnutrition. The National Kidney Foundation K/DOQI Clinical Practice Guidelines recommend a reduction in fasting LDL‐C below 100 mg/dL for the prevention of CVD in dialysis patients. Practically, however, the use of non‐HDL‐C measured by casual blood samples might be sufficient for the risk assessment in many hemodialysis patients. Statins are a good choice for lipid‐lowering in dialysis patients. Furthermore, lipoprotein profile might be improved by an inventive use of dialyzer membranes, dialysate solutions, and other dialysis‐related medications. For severe hypercholesterolemia, LDL‐apheresis is another choice for consideration. Further studies are needed to clearly prove the benefit of lipid reduction in hemodialysis patients and those with CKD at earlier stages.
Current Clinical Aspects of Dialysis‐Related Amyloidosis in Chronic Dialysis Patients
Authors: Saito Akihiko , Gejyo Fumitake
Published: August 2006

Abstract:  The current understanding of dialysis‐related amyloidosis has evolved over the past two decades. In the early 1980s, several researchers found amyloid deposits in the synovia of carpal tunnel syndrome (CTS), which have been recognized as a complication of chronic hemodialysis. The enigma was resolved in 1985, when β2‐microglobulin (β2‐m) with a molecular weight of 12 000 Da was identified as the major constitutional protein of this amyloid. Amyloid fibrils of this type that contain the sub‐unit protein of human leukocyte antigens (HLA), β2‐m, deposit predominantly in osteoarticular tissues, inducing musculoskeletal symptoms such as CTS, polyarthralgia, bone cyst showing radiolucency at X‐ray examination and destructive spondyloarthropathy. In addition, extra articular symptoms such as ischemic colitis, megaloglossia, and heart failure, that is, systemic involvement occasionally occur. We confirmed that the prevalence of CTS increases with duration of dialysis. Most patients with CTS associated with β2‐m amyloid deposits have undergone hemodialysis for 10 years or more. Up to 50% of patients had developed this complication after 20 years and the percentage was even higher after 25 years. General categories of therapeutic approaches for amyloidosis include prevention of onset or progression, symptomatic therapy (conservative treatment, orthopedic procedures, and physiotherapy), and renal transplantation. It is critical to elucidate the detail mechanisms of the amyloid fibril formation, and establish its radical treatment. It is also important to develop novel therapies such as cell implantation to compensate for normal kidney functions of uremic toxin protein metabolism.
New Therapeutic Option for Autosomal Dominant Polycystic Kidney Disease Patients With Enlarged Kidney and Liver
Authors: Ubara Yoshifumi
Published: August 2006

Abstract: The kidneys of patients with autosomal dominant polycystic kidney disease (ADPKD) usually continue to increase in size even after patients begin dialysis, and mass effects can lead to severe complications. Thus far, renal manifestations of this disorder have been discussed only from the viewpoint of cyst formation or cytogenesis, not from that of vascular abnormality. Because kidneys in ADPKD patients are usually supplied by well‐developed arteries, we attempted renal contraction therapy in ADPKD patients with renal transcatheter arterial embolization (TAE) using intravascular coils. Mainly peripheral branches of renal arteries encircling the cysts were embolized. Our treatment has been confirmed to be effective in 266 patients until 2005. Renal size continued to decrease to 53% of the pre‐TAE after 1 year. Almost all patients have had improved quality of life and nutritional status. We next tried TAE in 76 intractable patients with symptomatic polycystic liver. We tried to embolize only the hepatic segments replaced by cystic lesions in which the hepatic arteries were well‐developed but the intrahepatic portal vein was obstructed. Sixty‐four patients have had a good clinical course with this method. Based on our observation of ADPKD through treatment with TAE, we speculate that cyst growth in both the kidney and the liver progresses via the mechanism of ‘arteriogenesis’ of large vessels as well as ‘angiogenesis’ of small vessels.
Present Status and Perspective of the Development of a Bioartificial Kidney for Chronic Renal Failure Patients
Authors: Saito Akira , Aung Tun , Sekiguchi Koji , Sato Yoshinobu
Published: August 2006

Abstract:  A bioartificial tubule device was applied for the treatment of 10 acute renal failure and multiple organ failure patients by Humes et al. A bioartificial kidney for chronic renal failure patients, however, has never been applied. In order to develop a bioartificial kidney for preventing and treating long‐term complications of maintenance dialysis patients, we have to overcome difficulties such as antithrombogenic issue of hemofilters and development of long functioning tubule devices in the context of economical and easy treatment. Continuous hemofilters should modify with an antithrombogenic material on the inner surfaces of membranes to get more hemocompatible characteristics. We are developing an antithrombogenic continuous hemofilter coating with methacryloyloxyethyl phosphorylcholine polymer which will mimic phospholipid layers of human cell membrane on the inner surface of a hemofilter. The transportability of H2O, Na+, and glucose of bioartificial tubule devices using polysulfone hollow fiber modules and porcine proximal tubular epithelial cells LLC‐PK1 were evaluated using two kinds of circuits of different medium inside and outside of the cell‐attached hollow fiber membrane. Transport of H2O, Na+, and glucose were significantly increased when 2.5 g/dL of albumin was added, and plateaued on the eight day and then decreased thereafter until the 13th day. Transfection of a specific gene into human tubular epithelial cells might be required to keep contact inhibition in order to maintain a confluent monolayer for longer duration.
Therapeutic Strategies for Secondary Hyperparathyroidism in Dialysis Patients
Authors: Ogata Hiroaki , Koiwa Fumihiko , Ito Hidetoshi , Kinugasa Eriko
Published: August 2006

Abstract:  Secondary hyperparathyroidism (SHPT) leads not only to bone disorders, but also to cardiovascular complications in long‐term dialysis patients. Conventional treatment with calcium (Ca) supplement, phosphate (P) binders and active vitamin D analogs lead in part to amelioration of SHPT, but are simultaneously associated with unacceptable side‐effects, including hypercalcemia, hyperphosphatemia, and increased Ca × P products, which are the risk factors for cardiovascular disease in dialysis patients. Conventional treatment has been unable to facilitate the attainment of optimal management of SHPT proposed in the K/DOQI guidelines. Cinacalcet HCl (cinacalcet), a novel calcimimetic compound, restores the sensitivity of the Ca‐sensing receptor in parathyroid cells, and decreases serum parathyroid hormone (PTH) without introducing hypercalcemia or hyperphosphatemia. Cinacalcet treatment enables a significant number of patients to achieve the K/DOQI guideline. Based on experimental data, calcimimetics could ameliorate cardiovascular calcification and remodeling in uremic rats with SHPT. Clinical trials have shown that cinacalcet significantly reduced the risks of parathyroidectomy, fracture and cardiovascular hospitalization among long‐term dialysis patients with SHPT. Parathyroid intervention therapy (parathyroidectomy and percutaneous direct injection) is also a useful alternative. In the present article, we review novel therapeutic strategies for SHPT.
OPTIMIZATION OF SPRAY DRYING CONDITIONS FOR PRODUCTION OF BIFIDUS MILK POWDER FROM COW MILK
Authors: SELVAMUTHUKUMARAN M. , SHUKLA SHIV SHANKAR
Published: August 2006

Bifidus milk powder was prepared by supplementing cow's milk with predetermined level of additives to obtain slurry of desired concentration. The slurry was sterilized, cooled and inoculated with 24‐h‐old bulk culture of Bifidobacterium bifidum at 10% and incubated at 37C for 24 h, cooled and dried in SM Scientech Lab model spray dryer with predetermined spray drying conditions. The bifidus milk powder contains bifidobacteria counts from 1.88 × 109 to 15.80 × 109 cells/g dry weight and their percent survival was 4.17–35.11%. Maximum survival was obtained by using the following spray drying conditions: inlet temperature of 164.02C, slurry concentration of 25.62% total soluble solids and air pressure of 2.5 kg/cm2. The high temperature and air pressure of spray drying markedly influenced the color and appearance of final product. The inlet temperature and air pressure showed a significant effect on survival of bifidobacteria in the final product.
PREDICTING SENSORY ATTRIBUTE INTENSITIES AND CONSUMER ACCEPTANCE OF STORED ROASTED PEANUTS USING INSTRUMENTAL MEASUREMENTS
Authors: LEE C.M. , RESURRECCION A.V.A.
Published: August 2006

The objective of this study was to predict the sensory properties of stored roasted peanuts using instrumental methods. Roasted peanuts were stored at 20 treatment combinations of temperature (23, 30, 35 and 40C) and water activity (Aw; 0.33, 0.44, 0.54, 0.67 and 0.75 Aw), then evaluated after storing for up to 91 days using descriptive analysis (n = 12) and instrumental methods. Stored samples were also evaluated by consumers (n = 50). Regression models (adj. R2 ≥ 0.70) indicated that increasing storage Aw resulted in decreasing color lightness (L value). Increasing storage time and Aw increased both measured Aw and percent moisture of roasted peanuts. Sensory texture attribute intensities were best predicted by percent moisture (adj. R2 ≥ 0.78), whereas consumer ratings were best predicted (adj. R2 ≥ 0.74) by color or percent moisture. Instrumental texture analyses did not predict descriptive or consumer ratings. While percent moisture was the best predictor of consumer acceptance of stored roasted peanuts, color was an excellent alternative predictor and employed a much simpler assay.
DETECTION OF STAPHYLOCOCCAL ENTEROTOXIN A FROM RICOTTA CHEESE BY CELL CULTURE
Authors: NORMANNO G. , DAMBROSIO A. , QUAGLIA N.C. , LORUSSO V. , MERICO A. , GERMINARIO G.L. , ABENANTE R.P. , NARCISI D. , FIRINU A. , CELANO G.V.
Published: August 2006

Staphylococcal food poisoning (SFP) is a very common foodborne disease. Milk and dairy products are frequently contaminated with enterotoxigenic Staphylococcus aureus, which are often involved in SFP. These foods may become contaminated owing to subclinical staphylococcal mastitis or during handling, storage and trade. For sanitary purposes, an effective approach is to detect the staphylococcal enterotoxins directly in foods, rather than detect, count and type the isolated S. aureus strains, because the toxin is the causative agent of foodborne illness. This paper illustrates a cell‐based bioassay that uses the PEB (bovine embryo lung cells) cell line to detect staphylococcal enterotoxin type A (SEA) directly from artificially contaminated ricotta cheese. The test was able to detect SEA in the contaminated samples after 24 and 48 h of incubation at 37C, while results were uncertain when the samples were incubated for 72 h. The test proved to be easy to use and rapidly provided results.
TOTAL AND SOLUBLE DIETARY FIBER VARIATION IN CYAMOPSIS TETRAGONOLOBA (L.) TAUB. (GUAR) GENOTYPES
Authors: KAYS SANDRA E. , MORRIS J.B. , KIM YOOKYUNG
Published: August 2006

The endosperm of guar seed is the source of a soluble hydrophilic polysaccharide gum that is used as an emulsifier, thickener and stabilizer in a wide range of foods and is part of the seed total dietary fiber (TDF). This study examined the content and variation in TDF and soluble dietary fiber (SDF) in seeds of guar, Cyamopsis tetragonoloba (L.) Taub., accessions with diverse morphological traits. TDF and SDF, respectively, made up 52–58% (n = 9 accessions) and 26–32% (n = 8 accessions) of seed dry weight. Both TDF and SDF displayed significant genotypic variability. The magnitude of the variability indicates the possibility of improving these traits through plant breeding. Variability of protein, lipid, ash and dry matter content of seed was also observed.
ACOUSTIC IMPULSE RESPONSE FOR MEASURING THE FIRMNESS OF MANDARIN DURING STORAGE
Authors: WANG JUN , GÓMEZ ANTIHUS HERNÁNDEZ , PEREIRA ANNIA GARCIA
Published: August 2006

The objective of this research was to evaluate the ability of acoustic impulse response for monitoring the mandarin firmness change during storage. The dominant resonant frequency, stiffness coefficient (SC) and elasticity coefficient (EC) decrease with storage time. A good correlation was established between the acoustic parameters (SC and EC) and fruit compression force, and the correlation coefficients were 0.88 and 0.92, respectively. Acoustic impulse response gives a good indication of firmness change for mandarin during storage. The change of EC was more prominent (greatest), and hence it can be a better index of mandarin firmness. The nondestructive acoustic test might replace conventional destructive test for mandarin to determine fruit firmness and expected shelf life.
CHARACTERIZATION OF RECONSTITUTED MILK POWDER BY ULTRASOUND SPECTROSCOPY
Authors: MEYER STEFAN , RAJENDRAM VIJAYA S. , POVEY MALCOLM J.W.
Published: August 2006

When instant milk powder (IMP) is reconstituted with water, the product should resemble fresh milk. However, undissolved particles were found at the surface and in the bulk of the product. A visual reconstitution test (RT) is made on IMP to determine the reconstituted quality of the product. This test is directly linked to the presence of the undissolved particles. The particles found at the surface are formed by clustered liquid‐fat aggregates, which rise to the top of the milk and may give an impression of spoiled milk. The particles found in the bulk are small particles in the solution mostly composed of a protein gel. Because the repeatability and precision of the RT are very poor, a quantitative analytical technique is desirable. In this study we investigated five different quality milk powders by an ultrasound spectroscopy technique. The ultrasonic velocity and attenuation parameters were measured with a frequency scanning pulse echo reflectometer. We found that the ultrasonic velocity cannot be correlated to RT because the predominant phenomenon that affects the ultrasonic velocity is the physical state of the different components of the milk matrix (liquid fat, crystalline fat and lactose crystals), and this physical state is not a significant factor in powder quality. However, the ultrasonic attenuation coefficient is well correlated with RT. This is because, between two different quality powders, the most important factor that causes variation in the attenuation is scattering, correlated to particle size and to volume fraction rather than by the composition or physical state of the matrix and the same particle size factor, and volume fraction factor characterizes the powder reconstitution's quality.
PHYSICAL AND SENSORY CHARACTERISTICS OF FRIED COWPEA (VIGNA UNGUICULATA L. WALP) PASTE FORMULATED WITH SOY FLOUR AND EDIBLE COATINGS
Authors: HUSE H.L. , HUNG Y.‐C. , MCWATTERS K.H.
Published: August 2006

Akara, a popular West African fried food made from dry cowpeas, contains about 31% fat on a dry weight basis. Previous work in our laboratory showed that akara made from a 94% cowpea flour/6% soy flour blend plus edible coatings absorbed 26% less oil during frying than akara made from 100% cowpea. The objective of the present study was to determine the quality and acceptance of modified akara, either freshly fried (one‐stage) or partially fried/frozen/thawed/finish‐fried (two‐stage) as would be employed in the home or a foodservice setting. Soy‐substituted akara was firmer than freshly fried, 100% cowpea (control) akara. Methylcellulose‐coated akara was significantly different in total color from the control. Consumer acceptance studies indicated that, compared with two‐stage fried/100% cowpea akara, the two‐stage fried/6% soy formulation had similar hedonic ratings for flavor, texture, oiliness and overall acceptance. Sensory evaluation also indicated that two‐stage fried/6% soy akara with edible coatings was considered unacceptable (ratings < 5.0).
BITTER TASTE AND PHENOLIC COMPOUNDS IN EXTRA VIRGIN OLIVE OIL: AN EMPIRICAL RELATIONSHIP
Authors: SILIANI SILVIA , MATTEI ALISSA , INNOCENTI LUCA BENEVIERI , ZANONI BRUNO
Published: August 2006

Bitter taste of extra virgin olive oil is known to be affected by the phenolic composition. However, contribution of each individual phenol to this sensory note has not been clearly defined. The aims of this study were to verify whether there was a relationship between bitter sensation and phenolic compound concentration, to determine which compounds were involved in bitter taste and to evaluate quantitatively this correlation. Results confirmed that a positive correlation did exist between total phenolic amount and bitter intensity. Data processing showed that this correlation was significantly dependent upon a relationship between oleuropein aglycon (3,4‐DHPEA‐EA) and bitter intensity. An empirical exponential model was set up and validated.
Cherishing the Goose with the Golden Eggs: Trends in Migrant Remittances from Europe to Morocco 1970–2004
Authors: Haas de Hein , Plug Roald
Published: August 2006

In contrast to earlier predictions, migrant remittances from Europe to Morocco have shown an increasing trend over the past decades. Remittances constitute a vital and relatively stable source of foreign capital. The so-called “euro effect” and concomitant money laundering can only explain part of the recent, extreme surge in remittances. The structural solidity of remittances is explained by the unforeseen persistence of migration to northwestern Europe; new labor migration toward southern Europe; and the durability of transnational and transgenerational links between migrants and stay-behinds. The stable economic-political environment and new “enlightened” policies toward migrants explain why Morocco has been relatively successful in channeling remittances through official channels.
From Filial Piety to Religious Piety: Evangelical Christianity Reconstructing Taiwanese Immigrant Families in the United States
Authors: Chen Carolyn
Published: August 2006

While current scholarship suggests that immigrant religion reproduces ethnic traditions, this article suggests that religion can also challenge and transform ethnic traditions. Like other immigrants from Confucian cultures, Taiwanese immigrants find that their Confucian family traditions are difficult to maintain in the United States. The immigrant church is an important community institution that offers new models of parenting and family life. This article discusses how through the influence of evangelical Christianity, the immigrant church reconstructs Taiwanese immigrant families by (i) shifting the moral vocabulary of the family from one of filial duty to religious discipleship; (ii) democratizing relationships between parents and children; and (iii) consecrating the individuality and autonomy of children. These new models of family life both reproduce and alter Taiwanese traditions in the United States. Religion mediates and shapes immigrant cultural assimilation to the United States.
Labor Market Impact of Migration: Employment Structures and the Case of Greece
Authors: Cavounidis Jennifer
Published: August 2006

The impact of migration on the labor markets of host countries has fueled research and policy debates. While the impact of migration on the employment opportunities and wages of natives has come under extensive focus, another dimension of labor market impact of migration apparent in the case of Greece, the relations under which work is performed, has attracted less attention. The prevalence of family-based forms of production and the relatively limited extent of waged employment have long made Greece an outlier with respect to European employment structures. However, much of the work previously carried out within the framework of the family is now undertaken by migrants for wages. This substitution of unpaid family labor by migrant wage-labor is contributing to the convergence of Greek employment structures with those of other countries of the European Union.
Why Did House Members Vote for H.R. 4437?
Authors: Fetzer Joel S.
Published: August 2006

This article examines why members of the U.S. House of Representatives voted for H.R. 4437, the controversial 2005 bill to construct a 700-mile immigration barrier along the U.S.-Mexican border and to criminalize illegal presence and aid to undocumented immigrants. Logit analysis suggests that being a first-term House member or a Republican and representing a district that was in the South or the West or heavily blue-collar substantially boosted the odds of supporting H.R. 4437. If a member's district was disproportionately Asian, Latino, or, especially, African American, he or she was instead more likely to oppose the measure.
Gender Differences in Patenting in the Academic Life Sciences
Authors: Ding Waverly W. , Murray Fiona , Stuart Toby E.
Published: August 2006

We analyzed longitudinal data on academic careers and conducted interviews with faculty members to determine the scope and causes of the gender gap in patenting among life scientists. Our regressions on a random sample of 4227 life scientists over a 30-year period show that women faculty members patent at about 40% of the rate of men. We found that the gender gap has improved over time but remains large.
Comment on "Post-Wildfire Logging Hinders Regeneration and Increases Fire Risk"
Authors: Newton M. , Fitzgerald S. , Rose R. R. , Adams P. W. , Tesch S. D. , Sessions J. , Atzet T. , Powers R. F. , Skinner C.
Published: August 2006

Donato
et al
. (Brevia, 20 January 2006, p. 352) concluded that logging after wildfire kills natural regeneration and increases fire risk. We argue that their paper lacks adequate context and supporting information to be clearly interpreted by scientists, resource managers, policy-makers, and the public.
Response to Comments on "Post-Wildfire Logging Hinders Regeneration and Increases Fire Risk"
Authors: Donato D. C. , Fontaine J. B. , Campbell J. L. , Robinson W. D. , Kauffman J. B. , Law B. E.
Published: August 2006

We reported that postfire logging 2 to 3 years after the 2002 Biscuit Fire was associated with significant mortality in natural conifer regeneration and elevated potential fire behavior in the short term as a result of increased surface fuel loads. We underscore the strength of our study design and statistical conclusions, provide additional details of the research setting and scope, and address comments pertinent to forest development and fire ecology.
Fibrin Fibers Have Extraordinary Extensibility and Elasticity
Authors: Liu W. , Jawerth L. M. , Sparks E. A. , Falvo M. R. , Hantgan R. R. , Superfine R. , Lord S. T. , Guthold M.
Published: August 2006

Blood clots perform an essential mechanical task, yet the mechanical behavior of fibrin fibers, which form the structural framework of a clot, is largely unknown. By using combined atomic force‐fluorescence microscopy, we determined the elastic limit and extensibility of individual fibers. Fibrin fibers can be strained 180% (2.8-fold extension) without sustaining permanent lengthening, and they can be strained up to 525% (average 330%) before rupturing. This is the largest extensibility observed for protein fibers. The data imply that fibrin monomers must be able to undergo sizeable, reversible structural changes and that deformations in clots can be accommodated by individual fiber stretching.
Comment on "Post-Wildfire Logging Hinders Regeneration and Increases Fire Risk"
Authors: Baird B. N.
Published: August 2006

Based on limited sampling 2 years after the 2002 Biscuit Fire in Oregon, Donato
et al
. (Brevia, 20 January 2006, p. 352) concluded that postfire logging reduced seedling regeneration by 71%. Analysis of the study methodology and raw data suggest that this estimate is statistically flawed and misleading and says nothing about the impacts of more prompt postfire harvest.
Crustal Dilatation Observed by GRACE After the 2004 Sumatra-Andaman Earthquake
Authors: Han Shin-Chan , Shum C. K. , Bevis Michael , Ji Chen , Kuo Chung-Yen
Published: August 2006

We report the detection of an earthquake by a space-based measurement. The Gravity Recovery and Climate Experiment (GRACE) satellites observed a ±15-microgalileo gravity change induced by the great December 2004 Sumatra-Andaman earthquake. Coseismic deformation produces sudden changes in the gravity field by vertical displacement of Earth's layered density structure and by changing the densities of the crust and mantle. GRACE's sensitivity to the long spatial wavelength of gravity changes resulted in roughly equal contributions of vertical displacement and dilatation effects in the gravity measurements. The GRACE observations provide evidence of crustal dilatation resulting from an undersea earthquake.
Synthesis of Biaryls via Catalytic Decarboxylative Coupling
Authors: Gooßen Lukas J. , Deng Guojun , Levy Laura M.
Published: August 2006

We present a safe and convenient cross-coupling strategy for the large-scale synthesis of biaryls, commercially important structures often found in biologically active molecules. In contrast to traditional cross-couplings, which require the prior preparation of organometallic reagents, we use a copper catalyst to generate the carbon nucleophiles in situ, via decarboxylation of easily accessible arylcarboxylic acid salts. The scope and potential economic impact of the reaction are demonstrated by the synthesis of 26 biaryls, one of which is an intermediate in the large-scale production of the agricultural fungicide Boscalid.
N- to C-Terminal SNARE Complex Assembly Promotes Rapid Membrane Fusion
Authors: Pobbati Ajaybabu V. , Stein Alexander , Fasshauer Dirk
Published: August 2006

Assembly of the soluble
N
-ethylmaleimide–sensitive factor attachment protein receptors (SNAREs) syntaxin 1, SNAP-25, and synaptobrevin 2 is thought to be the driving force for the exocytosis of synaptic vesicles. However, whereas exocytosis is triggered at a millisecond time scale, the SNARE-mediated fusion of liposomes requires hours for completion, which challenges the idea of a key role for SNAREs in the final steps of exocytosis. We found that liposome fusion was dramatically accelerated when a stabilized syntaxin/SNAP-25 acceptor complex was used. Thus, SNAREs do have the capacity to execute fusion at a speed required for neuronal secretion, demonstrating that the maintenance of acceptor complexes is a critical step in biological fusion reactions.
Anti-Inflammatory Activity of Immunoglobulin G Resulting from Fc Sialylation
Authors: Kaneko Yoshikatsu , Nimmerjahn Falk , Ravetch Jeffrey V.
Published: August 2006

Immunoglobulin G (IgG) mediates pro- and anti-inflammatory activities through the engagement of its Fc fragment (Fc) with distinct Fcg receptors (FcgRs). One class of Fc-FcgR interactions generates pro-inflammatory effects of immune complexes and cytotoxic antibodies. In contrast, therapeutic intravenous gamma globulin and its Fc fragments are anti-inflammatory. We show here that these distinct properties of the IgG Fc result from differential sialylation of the Fc core polysaccharide. IgG acquires anti-inflammatory properties upon Fc sialylation, which is reduced upon the induction of an antigen-specific immune response. This differential sialylation may provide a switch from innate anti-inflammatory activity in the steady state to generating adaptive pro-inflammatory effects upon antigenic challenge.
Reflections on Mind
Authors: Grusec Joan E.
Published: August 2006

An Argument for Mind
.
By Jerome Kagan
. Yale University Press, New Haven, CT, 2006. 301 pp. $27.50, £17.50. ISBN 0-300-11337-4.
Characterization of the Pilin Ortholog of theHelicobacter pyloriType IVcagPathogenicity Apparatus, a Surface-Associated Protein Expressed during Infection
Authors: Andrzejewska Joanna , Lee Sae Kyung , Olbermann Patrick , Lotzing Nina , Katzowitsch Elena , Linz Bodo , Achtman Mark , Kado Clarence I. , Suerbaum Sebastian , Josenhans Christine
Published: August 2006

TheHelicobacter pylori cagpathogenicity island (cagPAI) encodes components of a type IV secretion system (T4SS) involved in host interaction and pathogenicity. Previously, sevencagPAI proteins were identified as homologs ofAgrobacterium tumefaciensVir proteins, which form a paradigm T4SS. The T pilus composed of the processed VirB2 pilin is an external structural part of theA. tumefaciensT4SS. InH. pylori,cag-dependent assembly of pili has not been observed so far, nor has a pilin (VirB2) ortholog been characterized. We have here identified, using a motif-based search, anH. pylori cagisland protein (HP0546) that possesses sequence and predicted structural similarities to VirB2-like pilins of other T4SSs. The HP0546 protein displays interstrain variability in its terminal domains. HP0546 was expressed as a FLAG-tagged fusion protein inEscherichia coli,A. tumefaciens, andH. pyloriand was detected as either two or three bands of different molecular masses in the insoluble fraction, indicating protein processing. As reported previously, isogenicH. pylorimutants in the putativecagpilin gene had reduced abilities to inducecagPAI-dependent interleukin-8 secretion in gastric epithelial cells. Fractionation analysis ofH. pylori, using a specific antiserum raised against an N-terminal HP0546 peptide, showed that the protein is partially surface exposed and that its surface localization depended upon an intactcagsystem. By immunoelectron microscopy, HP0546 was localized in surface appendages, with surface exposure of an N-terminal epitope. Pronounced strain-to-strain variability of this predicted surface-exposed part of HP0546 indicates a strong selective pressure for variation in vivo.
Global Regulatory Impact of ClpP Protease ofStaphylococcus aureuson Regulons Involved in Virulence, Oxidative Stress Response, Autolysis, and DNA Repair
Authors: Michel Antje , Agerer Franziska , Hauck Christof R. , Herrmann Mathias , Ullrich Joachim , Hacker Jörg , Ohlsen Knut
Published: August 2006

Staphylococcus aureusis an important pathogen, causing a wide range of infections including sepsis, wound infections, pneumonia, and catheter-related infections. In several pathogens ClpP proteases were identified by in vivo expression technologies to be important for virulence. Clp proteolytic complexes are responsible for adaptation to multiple stresses by degrading accumulated and misfolded proteins. In this reportclpP, encoding the proteolytic subunit of the ATP-dependent Clp protease, was deleted, and gene expression of ΔclpPwas determined by global transcriptional analysis using DNA-microarray technology. The transcriptional profile reveals a strong regulatory impact of ClpP on the expression of genes encoding proteins that are involved in the pathogenicity ofS. aureusand adaptation of the pathogen to several stresses. Expression of theagrsystem andagr-dependent extracellular virulence factors was diminished. Moreover, the loss ofclpPleads to a complete transcriptional derepression of genes of the CtsR- and HrcA-controlled heat shock regulon and a partial derepression of genes involved in oxidative stress response, metal homeostasis, and SOS DNA repair controlled by PerR, Fur, MntR, and LexA. The levels of transcription of genes encoding proteins involved in adaptation to anaerobic conditions potentially regulated by an Fnr-like regulator were decreased. Furthermore, the expression of genes whose products are involved in autolysis was deregulated, leading to enhanced autolysis in the mutant. Our results indicate a strong impact of ClpP proteolytic activity on virulence, stress response, and physiology inS. aureus.
The Entry Mechanism of Membrane-Containing Phage Bam35 Infecting
Bacillus thuringiensis
Authors: Gaidelytė Aušra , Cvirkaitė-Krupovic Virginija , Daugelavicius Rimantas , Bamford Jaana K. H. , Bamford Dennis H.
Published: August 2006

The temperate double-stranded DNA bacteriophage Bam35 infects gram-positive
Bacillus thuringiensis
cells. Bam35 has an icosahedral protein coat surrounding the viral membrane that encloses the linear 15-kbp DNA genome. The protein coat of Bam35 uses the same assembly principle as that of PRD1, a lytic bacteriophage infecting gram-negative hosts. In this study, we dissected the process of Bam35 entry into discrete steps: receptor binding, peptidoglycan penetration, and interaction with the plasma membrane (PM). Bam35 very rapidly adsorbs to the cell surface, and
N
-acetyl-muramic acid is essential for Bam35 binding. Zymogram analysis demonstrated that peptidoglycan-hydrolyzing activity is associated with the Bam35 virion. We showed that the penetration of Bam35 through the PM is a divalent-cation-dependent process, whereas adsorption and peptidoglycan digestion are not.
Global Gene Expression Analysis of the Heat Shock Response in the Phytopathogen
Xylella fastidiosa
Authors: Koide Tie , Vêncio Ricardo Z. N. , Gomes Suely L.
Published: August 2006

Xylella fastidiosa
is a phytopathogenic bacterium that is responsible for diseases in many economically important crops. Although different strains have been studied, little is known about
X. fastidiosa
stress responses. One of the better characterized stress responses in bacteria is the heat shock response, which induces the expression of specific genes to prevent protein misfolding and aggregation and to promote degradation of the irreversibly denatured polypeptides. To investigate
X. fastidiosa
genes involved in the heat shock response, we performed a whole-genome microarray analysis in a time course experiment. Globally, 261 genes were induced (9.7%) and 222 genes were repressed (8.3%). The expression profiles of the differentially expressed genes were grouped, and their expression patterns were validated by quantitative reverse transcription-PCR experiments. We determined the transcription start sites of six heat shock-inducible genes and analyzed their promoter regions, which allowed us to propose a putative consensus for σ
32
promoters in
Xylella
and to suggest additional genes as putative members of this regulon. Besides the induction of classical heat shock protein genes, we observed the up-regulation of virulence-associated genes such as
vapD
and of genes for hemagglutinins, hemolysin, and xylan-degrading enzymes, which may indicate the importance of heat stress to bacterial pathogenesis. In addition, we observed the repression of genes related to fimbriae, aerobic respiration, and protein biosynthesis and the induction of genes related to the extracytoplasmic stress response and some phage-related genes, revealing the complex network of genes that work together in response to heat shock.
Growth Phase-Dependent Expression of Drug Exporters in
Escherichia coli
and Its Contribution to Drug Tolerance
Authors: Kobayashi Asuka , Hirakawa Hidetada , Hirata Takahiro , Nishino Kunihiko , Yamaguchi Akihito
Published: August 2006

Drug exporters contribute to the intrinsic drug resistance in many organisms. Although there are at least 20 exporter genes in
Escherichia coli
, most of them apparently do not confer drug resistance in complex laboratory media except for the AcrAB, EmrE, and MdfA efflux systems. In this study, we comprehensively investigated the growth phase-dependent expression of drug exporter genes. The expression of
acrAB
,
emrAB
,
emrD
,
emrE
,
emrKY
,
mdfA
, and
ydgFE
is stable at moderate levels during any growth phase, whereas
mdtEF
promoter activity greatly increased with cell growth and reached the maximum level at the late stationary phase. The growth phase-dependent increase in
mdtEF
expression was also observed on quantitative reverse transcription-PCR analysis. As expected from the transporter expression, the stationary-phase cells actually showed MdtEF-dependent tolerance to drugs and toxic dyes. Growth phase-dependent elevation of
mdtEF
expression was found to be mediated by the stationary-phase σ factor
rpoS
and the RpoS-dependent signaling pathway, Hfq, GadY, and GadX. The induction level was decreased by
tnaAB
deletion, suggesting that indole sensing stimulates this process.
Cyclic AMP-Dependent Osmoregulation of
crp
Gene Expression in
Escherichia coli
Authors: Balsalobre Carlos , Johansson Jörgen , Uhlin Bernt Eric
Published: August 2006

We have found that the cyclic AMP (cAMP) receptor protein (CRP)-cAMP regulatory complex in
Escherichia coli
is subject to osmoregulation at the level of
crp
gene expression. This osmoregulation was lost in a
cya
mutant strain but could be restored by external addition of cAMP, suggesting that the intracellular level of cAMP is a key factor in the osmoregulation of CRP. The ability of the cell to maintain optimal CRP activity was essential for the growth and survival of the bacteria under low-osmolarity conditions as shown by studies with different
crp
mutant alleles. A suppressor mutant with a novel amino acid substitution (L124R) in CRP showed restored growth at low osmolarity. CRP(L124R) was not activated by cAMP and was shown to be dominant negative over the wild type. Our findings suggest that the fine-tuning of the CRP activity may be critical for bacterial viability and adaptability to changing osmotic conditions.
Analysis of the Terminus Region of the
Caulobacter crescentus
Chromosome and Identification of the
dif
Site
Authors: Jensen Rasmus B.
Published: August 2006

The terminus region of the
Caulobacter crescentus
chromosome and the
dif
chromosome dimer resolution site were characterized. The
Caulobacter
genome contains skewed sequences that abruptly switch strands at
dif
and may have roles in chromosome maintenance and segregation. Absence of
dif
or the XerCD recombinase results in a chromosome segregation defect. The
Caulobacter
terminus region is unusual, since it contains many essential or highly expressed genes.
The Mycobacterium-Specific Gene Rv2719c Is DNA Damage Inducible Independently of RecA
Authors: Brooks Patricia C. , Dawson Lisa F. , Rand Lucinda , Davis Elaine O.
Published: August 2006

The mycobacterium-specific gene Rv2719c was found to be expressed primarily from a promoter that was clearly DNA damage inducible independently of RecA. Upstream of the transcriptional start site for this promoter, sequence motifs resembling those observed previously at the RecA-independent, DNA damage-induciblerecApromoter were identified, and the −10 motif was demonstrated by mutational analysis in transcriptional fusion constructs to be important for expression of Rv2719c.
Two Transsulfurylation Pathways in
Klebsiella pneumoniae
Authors: Seiflein Thomas A. , Lawrence Jeffrey G.
Published: August 2006

In most bacteria, inorganic sulfur is assimilated into cysteine, which provides sulfur for methionine biosynthesis via transsulfurylation. Here, cysteine is transferred to the terminal carbon of homoserine via its sulfhydryl group to form cystathionine, which is cleaved to yield homocysteine. In the enteric bacteria
Escherichia coli
and
Salmonella enterica
, these reactions are catalyzed by irreversible cystathionine-γ-synthase and cystathionine-β-lyase enzymes. Alternatively, yeast and some bacteria assimilate sulfur into homocysteine, which serves as a sulfhydryl group donor in the synthesis of cysteine by reverse transsulfurylation with a cystathionine-β-synthase and cystathionine-γ-lyase. Herein we report that the related enteric bacterium
Klebsiella pneumoniae
encodes genes for both transsulfurylation pathways; genetic and biochemical analyses show that they are coordinately regulated to prevent futile cycling.
Klebsiella
uses reverse transsulfurylation to recycle methionine to cysteine during periods of sulfate starvation. This
m
ethionine-
t
o-
c
ysteine (
mtc
) transsulfurylation pathway is activated by cysteine starvation via the CysB protein, by adenosyl-phosphosulfate starvation via the Cbl protein, and by methionine excess via the MetJ protein. While
mtc
mutants cannot use methionine as a sulfur source on solid medium, they will utilize methionine in liquid medium via a sulfide intermediate, suggesting that an additional nontranssulfurylation methionine-to-cysteine recycling pathway(s) operates under these conditions.
The GrlR-GrlA Regulatory System Coordinately Controls the Expression of Flagellar and LEE-Encoded Type III Protein Secretion Systems in EnterohemorrhagicEscherichia coli
Authors: Iyoda Sunao , Koizumi Nobuo , Satou Hitomi , Lu Yan , Saitoh Takehito , Ohnishi Makoto , Watanabe Haruo
Published: August 2006

The gene function of the locus of enterocyte effacement (LEE) is essential for full virulence of enterohemorrhagicEscherichia coli(EHEC). Strict control of LEE gene expression is mediated by the coordinated activities of several regulatory elements. We previously reported that the ClpX/ClpP protease positively controls LEE expression by down-regulating intracellular levels of GrlR, a negative regulator of LEE gene expression. We further revealed that the negative effect of GrlR on LEE expression was mediated through GrlA, a positive regulator of LEE expression. In this study, we found that the FliC protein, a major component of flagellar filament, was overproduced inclpXPmutant EHEC, as previously reported forSalmonella. We further found that FliC expression was reduced in aclpXP grlRdouble mutant. To determine the mediators of this phenotype, FliC protein levels in wild-type,grlR,grlA, andgrlR grlAstrains were compared. Steady-state levels of FliC protein were reduced only in thegrlRmutant, suggesting that positive regulation of FliC expression by GrlR is mediated by GrlA. Correspondingly, cell motility was also reduced in thegrlRmutant, but not in thegrlAorgrlR grlAmutant. Because overexpression ofgrlAfrom a multicopy plasmid strongly represses the FliC level, as well as cell motility, we conclude that GrlA acts as a negative regulator of flagellar-gene expression. The fact that an EHEC strain constitutively expressing FlhD/FlhC cannot adhere to HeLa cells leads us to hypothesize that GrlA-dependent repression of the flagellar regulon is important for efficient cell adhesion of EHEC to host cells.
Distinguishing Characteristics of Hyperrecombinogenic RecA Protein from
Pseudomonas aeruginosa
Acting in
Escherichia coli
Authors: Baitin Dmitry M. , Bakhlanova Irina V. , Kil Yury V. , Cox Michael M. , Lanzov Vladislav A.
Published: August 2006

In
Escherichia coli
, a relatively low frequency of recombination exchanges (FRE) is predetermined by the activity of RecA protein, as modulated by a complex regulatory program involving both autoregulation and other factors. The RecA protein of
Pseudomonas aeruginosa
(RecA
Pa
) exhibits a more robust recombinase activity than its
E. coli
counterpart (RecA
Ec
). Low-level expression of RecA
Pa
in
E. coli
cells results in hyperrecombination (an increase of FRE) even in the presence of RecA
Ec
. This genetic effect is supported by the biochemical finding that the RecA
Pa
protein is more efficient in filament formation than RecA K72R, a mutant protein with RecA
Ec
-like DNA-binding ability. Expression of RecA
Pa
also partially suppresses the effects of
recF
,
recO
, and
recR
mutations. In concordance with the latter, RecA
Pa
filaments initiate recombination equally from both the 5′ and 3′ ends. Besides, these filaments exhibit more resistance to disassembly from the 5′ ends that makes the ends potentially appropriate for initiation of strand exchange. These comparative genetic and biochemical characteristics reveal that multiple levels are used by bacteria for a programmed regulation of their recombination activities.