bluuebunny/crossref_metadata_2025 huggingface dataset:
Metapopulation ecology in the sea: from Levins' model to marine ecology and fisheries science
Authors: Kritzer Jacob P , Sale Peter F
Published: December 2004

Marine and fisheries scientists are increasingly using metapopulation concepts to better understand and model their focal systems. Consequently, they are considering what defines a metapopulation. One perspective on this question emphasizes the importance of extinction probability in local populations. This view probably stems from the focus on extinction in Levins' original metapopulation model, but places unnecessary emphasis on extinction–recolonization dynamics. Metapopulation models with more complex structure than Levins' patch‐occupancy model and its variants allow a broader range of population phenomena to be examined, such as changes in population size, age structure and genetic structure. Analyses along these lines are critical in fisheries science, where presence–absence resolution is far too coarse to understand stock dynamics in a meaningful way. These more detailed investigations can, but need not, aim to assess extinction risk or deal with extinction‐prone local populations. Therefore, we emphasize the coupling of spatial scales as the defining feature of metapopulations. It is the degree of demographic connectivity that characterizes metapopulations, with the dynamics of local populations strongly dependent upon local demographic processes, but also influenced by a nontrivial element of external replenishment. Therefore, estimating rates of interpopulation exchange must be a research priority. We contrast metapopulations with other spatially structured populations that differ in the degree of local closure of their component populations. We conclude with consideration of the implications of metapopulation structure for spatially explicit management, particularly the design of marine protected area networks.
Mapping global fisheries: sharpening our focus
Authors: Watson Reg , Kitchingman Adrian , Gelchu Ahmed , Pauly Daniel
Published: December 2004

Mapping global landings is an important prerequisite for examining causal relationships between fishing and ecological change. Landing statistics, typically provided with poor spatial precision, can be disaggregated into a grid system of spatial cells (30 min ×30 min) using a rule‐based approach and ancillary data about distributions of fished taxa and fishing access of reporting countries. Presentation of time series catch composition is then possible for many types of marine areas including biogeochemical provinces, large marine ecosystems and exclusive economic zones.
Density‐dependent habitat selection and the ideal free distribution in marine fish spatial dynamics: considerations and cautions
Authors: Shepherd Travis D , Litvak Matthew K
Published: December 2004

Current methods and theory used in the study of the spatial dynamics of marine fish are problematic. Positive relationships between population abundance and occupied area are typically interpreted as evidence of density‐dependent habitat selection. However, both abundance and area may co‐vary with an un‐parameterized variable, such as a density‐independent effect. In addition, if density‐dependent habitat selection is present, population growth rates in optimal habitats would be expected to be lower than in marginal habitats. This same pattern can also evolve from a large‐scale, spatially autocorrelated change in a density‐independent factor. The theory underlying density‐dependent habitat selection, the ideal free distribution, can be tautological when no a priori information of how habitat suitability changes with density is known. In this case, an ideal free distribution can be defined for any pattern of habitat‐specific population growth rates. However, these problems are not insurmountable and solutions may be found by considering spatial variation in proxies of fitness and explicitly allowing for the relative importance of habitat selection (density dependent) and environmental (density independent) effects to vary with spatial scale.
Testing hypotheses about fecundity, body size and maternal condition in fishes
Authors: Koops Marten A. , Hutchings Jeffrey A. , McIntyre Tara M.
Published: December 2004

Recent research suggests that maternal condition positively influences the number of eggs spawned in fishes. These studies commonly choose a priori to use body length rather than weight as an explanatory variable of offspring production, even though weight is usually the better predictor of fecundity. We are concerned that consistent exclusion of body weight as a predictor of egg production inflates the variance in fecundity attributable to maternal condition. By analysing data on three populations of Atlantic cod (Gadus morhua, Gadidae) and 10 populations of brook trout (Salvelinus fontinalis, Salmonidae), we illustrate the need for a statistically defensible method of model selection to distinguish the effects of maternal condition on egg production from the effects of body size alone. Forward stepwise regression and null model analyses reveal how length‐based regressions can significantly over‐estimate correlations between condition and fecundity, leading us to conclude that the effect of condition on egg productivity may not be as ubiquitous or as biologically important as previously thought. Our work underscores the need for greater statistical clarity in analyses of the effects of maternal condition on reproductive productivity in fishes.
Links between social and linguistic processing of speech in preschool children with autism: behavioral and electrophysiological measures
Authors: Kuhl Patricia K. , Coffey‐Corina Sharon , Padden Denise , Dawson Geraldine
Published: December 2004

Data on typically developing children suggest a link between social interaction and language learning, a finding of interest both to theories of language and theories of autism. In this study, we examined social and linguistic processing of speech in preschool children with autism spectrum disorder (ASD) and typically developing chronologically matched (TDCA) and mental age matched (TDMA) children. The social measure was an auditory preference test that pitted ‘motherese’ speech samples against non‐speech analogs of the same signals. The linguistic measure was phonetic discrimination assessed with mismatch negativity (MMN), an event‐related potential (ERP). As a group, children with ASD differed from controls by: (a) demonstrating a preference for the non‐speech analog signals, and (b) failing to show a significant MMN in response to a syllable change. When ASD children were divided into subgroups based on auditory preference, and the ERP data reanalyzed, ASD children who preferred non‐speech still failed to show an MMN, whereas ASD children who preferred motherese did not differ from the controls. The data support the hypothesis of an association between social and linguistic processing in children with ASD.
Young children's use of range‐of‐reference information in word learning
Authors: Hall D. Geoffrey , Bélanger Julie
Published: December 2004

An important source of information about a new word's meaning (and its associated lexical class) is its range of reference: the number of objects to which it is extended. Ninety toddlers (mean age = 37 months) participated in a study to determine whether young children can use this information in word learning. When a novel word was presented with unambiguous lexical class cues as either a proper name (i.e. ‘His name is DAXY’) or an adjective (i.e. ‘He is very DAXY’), toddlers interpreted it appropriately, regardless of whether it was applied to one or both members of a pair of identical‐looking stuffed animals. They restricted a proper name to the designated animal(s); but they generalized an adjective from the labeled animal(s) to a new animal bearing the same property. However, when the word was presented with no specific lexical class cues (i.e. ‘DAXY’), toddlers made significantly different interpretations, depending on the number of referents. When the word was applied to one animal, they restricted it to that animal (consistent with a proper name interpretation); when the word was applied to two animals, they generalized it to a new animal with the property (consistent with an adjective or a restricted count noun interpretation). Range‐of‐reference information thus provided toddlers with a default cue to the meaning (and associated lexical class) of a novel word.
Maladaptive conflict monitoring as evidence for executive dysfunction in children with chromosome 22q11.2 deletion syndrome
Authors: Bish Joel P. , Ferrante Samantha M. , McDonald‐McGinn Donna , Zackai Elaine , Simon Tony J.
Published: December 2004

Using an adaptation of the Attentional Networks Test, we investigated aspects of executive control in children with chromosome 22q11.2 deletion syndrome (DS22q11.2), a common but not well understood disorder that produces non‐verbal cognitive deficits and a marked incidence of psychopathology. The data revealed that children with DS22q11.2 demonstrated greater difficulty than controls in locating and processing target items in the presence of distracters. Importantly, children with DS22q11.2 showed a deficit in the ability to monitor and adapt to stimulus conflict. These data provide evidence of inadequate conflict adaptation in children with DS22q11.2, a problem that is also present in schizophrenia. The findings of specific executive dysfunction in this group may provide a linkage between particular genetic abnormalities and the development of psychopathology.
Disentangling dimensions in the dimensional change card‐sorting task
Authors: Kloo Daniela , Perner Josef
Published: December 2004

The dimensional change card‐sorting task (DCCS task) is frequently used to assess young children's executive abilities. However, the source of children's difficulty with this task is still under debate. In the standard DCCS task, children have to sort, for example, test cards with a red cherry or a blue banana into two boxes marked with target cards showing a blue cherry and a red banana. Typically, 3‐year‐olds have severe problems switching from sorting by one dimension (e.g. color) to sorting by the other dimension (e.g. shape). Three experiments with 3‐ to 4‐year‐olds showed that separating the two dimensions as properties of a single object, and having them characterize two different objects (e.g. by displaying an outline of a cherry next to a red filled circle on the card) improves performance considerably. Results are discussed in relation to a number of alternative explanations for 3‐year‐olds’ difficulty with the DCCS task.
Some comments on specification tests in nonparametric absolutely regular processes
Authors: Dette Holger , Spreckelsen Ingrid
Published: December 2004

In this note, several aspects of a recently proposed specification test in nonparametric models driven by an absolutely regular process are discussed. In particular, we give a more detailed asymptotic analysis of tests based on kernel methods under fixed alternatives using a central limit theorem for U‐statistics with n‐dependent nondegenerate kernel. As a by‐product, it is demonstrated that several results regarding the asymptotic distribution or goodness‐of‐fit tests are incorrectly stated in the literature. Our result also indicates that results on the asymptotic equivalence of nonparametric autoregression and nonparametric regression cannot be used for the asymptotic analysis of goodness‐of‐fit tests under fixed alternatives.
Animal assisted therapy for people with dementia
Authors: MOTOMURA Naoyasu , YAGI Takayoshi , OHYAMA Hitomi
Published: December 2004

Background: The effects of animal assisted therapy on patients with dementia were investigated through the use of mental state batteries.

Methods: The subjects were eight patients admitted in a local nursing home. Their mean age was 84.8 years ±7.0; four were dementia of Alzheimer's type patients, and the others were vascular dementia patients. Mental state tests included the apathy scale, the irritability scale, the depression scale, the activities of daily living and mini‐mental state examination. Dog therapy with two dogs from the Japanese Rescue Association took place for 1 h over four consecutive days.

Results: The patients could communicate with and observe the dogs, and the dogs could interact with the humans. The results indicated no significant difference in the irritability scale, the depression scale, activity of daily living and mini‐mental state examination. However, most patients had a good impression of dog therapy, and all improved their apathetic state.

Conclusions: These results might imply that animal assisted therapy has the possibility to influence the mental state of patients with dementia.
Physiology in daily hemodialysis in terms of the time average concentration/time average deviation concept
Authors: Lopot Frantisek , Nejedlý Bohdan , Sulková Sylvie
Published: December 2004

Quotidian or “daily" hemodialysis (DHD) is practiced in widely differing schedules. Yet all those schedules are reported to significantly ameliorate clinical outcome of patients. It is, however, not clear what is the actual cause of this amelioration. Rational possibilities include increased overall dialysis dose and increased weekly time. Conventional mathematical approaches (Kt/Vurea concept, equivalent renal clearance) cannot be used to study those issues because they do not consider number of dialysis per week and thus ignore the issue of treatment schedule “unphysiology.” The time average concentration/time average deviation (TAC/TAD) concept may well be used to visualize impact of treatment schedule on both plasma urea profile statics (TAC) and dynamics (TAD). The concept may further help to stratify studies for elucidation of the key factors of clinical outcome improvement seen on DHD. Actual physiologic mechanisms responsible for this improvement are to be sought among those with having derivative component (i.e., reacting to the rate of a change rather than to the magnitude of the change). It should, however, be kept in mind that the TAC/TAD concept is able to assess unphysiology of a treatment schedule, not unphysiology of a single treatment session.
Blood access in daily hemodialysis
Authors: Twardowski Zbylut J.
Published: December 2004

Frequent dialyses are sometimes perceived as increasing the risk of blood access malfunction and decreased longevity. This review of the literature, however, indicates that the failure rates and overall fistula survival appear to be better with more frequent dialyses than with routine dialysis frequency, although the reasons for this phenomenon are not clear. One of the possible explanations is that frequent dialyses are associated with fewer intradialytic hypotensive episodes, which are very detrimental to the blood access. Another possible explanation is the generally lower blood flow used with more frequent hemodialyses, particularly long nocturnal hemodialysis. Finally, a decreased clotting tendency and decreased rates of hematoma formation at the puncture sites are additional possible explanations. Complication rates with bridge grafts are not higher with more frequent compared to routine thrice‐weekly hemodialysis sessions. No such comparative data are available, however, for central‐vein catheters. This lack of comparisons seems to stem from the intuitive assumption by nephrologists that hemodialyses that are more frequent should not adversely impact catheter complication rates and survival. No data at all are available on the use of the Dialock® hemodialysis system (Biolink Corp., Norwell, MA, USA) and LifeSite® hemodialysis access system (Vasca, Inc., Tewksbury, MA, USA), two newer forms of hybrid access in patients undergoing frequent hemodialyses. Current evidence shows that the perceived risk of blood access malfunction and decreased longevity when patients undergo more frequent hemodialysis is not supported by the current literature.
Nephrology Ethics: “No Dialysis” As a Treatment Option
Authors: Vachharajani T.J. , Atray N.K.
Published: December 2004

Background:  Renal failure in elderly patients often generates an ethical question “should dialysis be initiated?” The nephrologists are faced with the dilemma of conveying the prognosis of renal failure in elderly patients and also explain the pros and cons of offering a renal replacement therapy (RRT).

Methods:  We report a retrospective study conducted between 6/2001 and 6/2003 to evaluate the clinical situations where initiating RRT was considered inappropriate. All patients who opted for not initiating/withdrawal of RRT were included in the study.

Results:  Twenty‐four patients were included in the study. All patients were males with average age 70.7 years. 17/24 were in the intensive care unit. Complex medical illnesses with poor quality of life were the major reasons for opting out of RRT. 20/24 patients opted for not initiating RRT and 3/24 patients opted for withdrawal. 1/24 opted for a trial of RRT before taking long‐term decisions. 3/20 who opted against initiating RRT had advanced directives. 18/20 who opted for not initiating RRT died within 3 days of the need for RRT, 2/20 are alive without RRT after 6 and 4 months with estimated GFR of 14 and 12 mL/min, respectively. Patient who opted for a trial of RRT died eventually, 4 months after a prolonged bedridden stay in a nursing home. 3/3 ESRD patients died within a week after withdrawing dialysis.

Conclusion:  The decision to initiate RRT should be made considering the overall prognosis. A decision to not initiate or withdraw RRT is possible in critically ill patients and if taken judiciously can reduce physical and mental stress of both patient and their family members.
A Report on 4 New Cases of Nephrogenic Fibrosing Dermopathy in Chronic Hemodialysis Patients
Authors: Sreenarasimhaiah V. , Brown W. , Gellens M. , Philipneri M. , Flynn L. , Joseph A. , Bastani B.
Published: December 2004

Nephrogenic fibrosing dermopathy (NFD) is a rare entity affecting patients with renal failure, often on chronic dialysis or after transplantation (TXP). The patient profile at risk for this debilitating condition is yet undefined as is the role of renal failure in its etiology. We diagnosed 4 chronic hemodialysis (HD) patients with NFD. A 55‐year‐old Caucasian male on HD for 5 years, secondary to diabetic nephropathy, developed woody, indurated skin of the extremities, decreased mobility, and wheelchair dependence. He died within 1 year. A 66‐year‐old African‐American male with diabetes, hypertension, and pancreatic cancer developed thick indurated skin on his extremities after being on HD for approximately 20 months. He died 3 months later from sepsis. A 26‐year‐old Caucasian female on HD for approximately 10 years, secondary to hyperoxaluria‐induced renal failure, had undergone combined liver and kidney TXP with primary nonfunction of the renal TXP. She succumbed to cholangitis approximately 1 year after progressive skin thickening and joint contractures were noted. A 75‐year‐old Caucasian female with renal failure secondary to recurrent hemolytic uremic syndrome and TXP failure was dialysis dependent for 6 years. Over a 3‐month period, she developed skin changes consistent with NFD and entered hospice care secondary to marked deterioration in her quality of life. In all of these cases, skin changes were restricted to the extremities, sparing the trunk, face, and internal organs. Skin biopsy findings included thickened dermis with particularly thickened collagen bundles, mucin deposition, and fibroblast proliferation and were distinct from scleromyxedema and scleroderma. Autoimmune disease workup was negative. Indeed, NFD is a novel cutaneous fibrosing disorder of progressively debilitating nature in patients with renal failure that needs further clinical and pathological characterization.
Using the Laser in Correcting Anemia in Hemodialysis Patients
Authors: Ismagilov R.Z. , Dreizin V.U. , Azhitaeva A.S.
Published: December 2004

One of the main symptoms of terminal‐stage chronic renal insufficiency is anemia. One of the best applicable methods correcting anemia is using recombinant human erythropoietin preparation. Using recombinant human erythropoietin in patients with terminal‐stage chronic renal insufficiency in 90–95% of events had a positive effect, but 5–10% of patient had refraction to erythropoietin, which has spurred the search for new efficient methods correcting anemia. The purpose of the study was to determine the influence of the laser on erythropoiesis and blood acid–alkaline condition (pH) in patients with terminal‐stage chronic renal insufficiency. In the course of the study, erythrocytes, hemoglobin, reticulocytes in blood, and blood acid–alkaline condition (pH) were determined. At the beginning of the treatment, all hematological parameters 5 and 15 days after marrow stimulation were defined. 15 days after marrow stimulation with laser, increasing amounts of erythrocytes, hemoglobin, and hematocrit were observed. The initial erythrocyte count was 2.22 ± 0.1 × 1012/L, hemoglobin 67.7 ± 3.2 g/L and hematocrit 18.2 ± 1.2%. During the laser treatment, erythrocyte count increased up to 2.9 ± 0.8 × 1012/L, hemoglobin up to 89.6 ± 2.9 g/L and hematocrit up to 28.2 ± 1.3% (p < 0005).
The Effect of Increasing Blood Flow Rate on Dialysis Adequacy in Hemodialysis Patients with Low Kt/V
Authors: Kim Y.o. , Song W.j. , Yoon S.a. , Shin M.j. , Song H.c. , Kim Y.s. , Kim S.y , Chang Y.s. , Bang B.k.
Published: December 2004

Dialysis adequacy indexed by Kt/V in hemodialysis (HD) patients is recommended as a single‐pool Kt/V of at least 1.2 per session thrice weekly. But many patients cannot achieve this adequacy target. Although dialysis time is the most important as a factor influencing Kt/V, it is difficult to prolong dialysis time in practice because of its economic impact and poor patient compliance.

Objective:  The aim of this study is to investigate the effect of increasing blood flow rate on dialysis adequacy in HD patients with low Kt/V.

Methods:  This study enrolled 36 HD patients with single‐pool Kt/V <1.2 per session thrice weekly, which was measured in dialyzer blood flow rate of 230 mL/min. We increased 15% of blood flow rate in patients <65 kg of body weight and 20% in patients >65 kg. And then we compared Kt/V and urea reduction ratio (URR) between before and after increasing blood flow rate.

Results:  The mean age was 48 ± 11 years (23–73 years), and the number of males was 25. Of the total patients, 24 patients had dry weight <65 kg. Mean dialysis duration was 52 ± 50 months (3–216 months). Mean Kt/V before increasing blood flow rate was 1.02 ± 0.09. It increased to 1.14 ± 0.12 after increasing blood flow rate (p < 0.001). Of the total 36 patients, 13 patients (36.1%) achieved adequacy target (Kt/V ≤ 1.2). Mean URR before increasing blood flow rate was 56.9 ± 4.0%. It also increased to 60.8 ± 4.1% (p < 0.001).

Conclusion:  Our data suggest that increasing blood flow rate by 15–20% of previous flow rate is effective in achieving dialysis adequacy in HD patients with low Kt/V.
News and Traditional Indications from Short Daily Dialysis: Different Schemes to Optimized ESF Response
Authors: Barril G. , Besada E. , Caro P. , Dapena F. , Sanz P. , Cigarran S. , Selgas R.
Published: December 2004

Interest in quotidian (daily) hemodialysis (DHD) seems to be growing. DHD improves quality of life, blood pressure control, and nutrition, and decreases the need of medications, including erythropoiesis stimulating factors (ESF). We evaluate the short daily dialysis (SDHD) efficacy in 14 patients in conventional hemodialysis (HD) (3 weekly sessions/4 h), mean age 52.1 years, range 25–75, 10 males and 4 females, and found that they needed to increase dialysis efficiency by different medical indications: in 11 cases traditional indications – 5 cases with hypertensive myocardiopathy and severe LVH (2 of them with low left ventricle ejection fraction), 2 cases with symptomatic, ischemic cardiopathy 2 patient with big body‐surface area and elevated phosphorus levels, and 2 patients by inadequate dialysis (infradialysis conditioning malnutrition status) secondary to HD with permanent catheter. In one female (25 yr old), SDHD was prescribed to improve cardiac toxicity secondary to chemotherapy for acute promyelocytic leukemia. The index resistance of ESF decreased since the first month, and the Aranesp doses decreased by more than 40%. 1 male (49 years) with nephrogenic fibrosing dermopathy showed skin lesions with osteoblastic transformation. The skin lesions were improving since the first week, obtaining a decrease of the index resistance ESF higher than 60% in the first month. 1 male with symptomatic obstructive hypertrophic myocardiopathy showed improvement of symptoms and quality of life since the first weeks, as well as echocardiograpic signs and improvement in Hb levels and decreasing dose of ESF. The schedule in all of them was 5–6 days/week sessions between 2.15 h and 3 h, depending on body‐surface area. To obtain a weekly Kt/V nearest to 4, HD sessions were realized in the hospital (7 pts) or in satellite unit (7 pts). The time remaining in this schedule was between 1 and 42 months. All the patients showed clinical improvement, subjective and objective, since the first week of start of SDHD. 3 patients could be included in Tx waiting list again. Anemia improved, decreasing index resistance of ESF. In relation with this, the time necessary to improve the response to ESF was different, showing a decrease in the first month higher than 40% in two cases dialyzing with a membrane high‐flux with pore size 100 A, appearing high Hb levels also in a polycystic patient always without ESF. We observed by analyzing the results in 12 stable patients; the patients with high‐flux dialyzers showed better response to ESF. Perhaps it could offer a better clearance of large molecules (inhibitor erythropoiesis factor and high molecular weight toxins) that participate to respond to ESF.

Conclusion:  Our experience shows new indications for SDHD with very good results. Anemia was improved in relation with SDHD, when synthetic high‐flux membranes and high pore size were used.
Chronic Hemodialysis in a Nigerian Teaching Hospital
Authors: Agaba E.I. , Lopez A. , Ma I. , Martinez R. , Tzamaloukas R.A. , Vanderjagt D.J. , Glew R.H. , Tzamaloukas A.H.
Published: December 2004

The Jos University Teaching Hospital (JUTH) has dialyzed >320 patients with ESRD since 1993.

Objective:  To identify differences, and their causes, in the practice of dialysis between Nigerian state‐owned dialysis units and U.S.A.

Methods:  We analyzed the characteristics of chronic dialysis at JUTH.

Results:  At JUTH, chronic dialysis is started at development of frank uremia (K/DOQI standard: creatinine clearance >10 mL/min, no overt uremia). Frequency of hemodialysis was 3 times weekly in 2 patients, twice weekly in 1 and once weekly or longer in 7 patients. Breakdowns in the dialysis machinery, which is outdated, forced additional decreases in the frequency of dialysis. Duration of a dialysis session was 4 h by prescription, but much longer in several sessions because of dialysis machine breakdown during the session (US standard: 4 h). 2 patients were dialyzed through arterio‐venous fistulas and 8 patients were dialyzed though temporary femoral vein dialysis catheters removed after each dialysis session. A vascular surgeon was unavailable. The urea reduction ratio was 45.38.6% (U.S.A target: 65%). The cost of the first dialysis session at JUTH is $160. With reuse of dialysis supplies, including dialyzers, dialysis tubing, femoral catheters, and guide wires, the cost of each subsequent dialysis session is $33. The minimal cost of dialysis with 3 dialysis sessions weekly and a new dialyzer every week is $501 per month. The cost of dialysis is borne exclusively by the patient. For comparison, average monthly income is $74 for unskilled laborers, $222 for dialysis technicians, $296 for dialysis nurses, and $889 for academic nephrologists. The low dose of dialysis has adverse effects on patient quality of life (frequent admissions with uremia). Despite notable exceptions (2 patients on dialysis for 12 and 9 years, respectively), survival of dialysis patients at JUTH appears to be poor.

Conclusions:  Underdialysis is frequent in Nigeria and is the consequence of socioeconomic conditions and technologic deficits. Removal of the economic burden of dialysis from the patients with ESRD is the first logical step toward correction of underdialysis.
Arbuscular mycorrhizal fungi benefit from 7 years of free air CO2 enrichment in well‐fertilized grass and legume monocultures
Authors: Gamper Hannes , Peter Markus , Jansa Jan , Lüscher Andreas , Hartwig Ueli A. , Leuchtmann Adrian
Published: December 2004

Rising atmospheric carbon dioxide partial pressure (pCO2) and nitrogen (N) deposition are important components of global environmental change. In the Swiss free air carbon dioxide enrichment (FACE) experiment, the effect of altered atmospheric pCO2 (35 vs. 60 Pa) and the influence of two different N‐fertilization regimes (14 vs. 56 g N m−2 a−1) on root colonization by arbuscular mycorrhizal fungi (AMF) and other fungi (non‐AMF) of Lolium perenne and Trifolium repens were studied. Plants were grown in permanent monoculture plots, and fumigated during the growth period for 7 years. At elevated pCO2 AMF and non‐AMF root colonization was generally increased in both plant species, with significant effects on colonization intensity and on hyphal and non‐AMF colonization. The CO2 effect on arbuscules was marginally significant (P=0.076). Moreover, the number of small AMF spores (≤100 μm) in the soils of monocultures (at low‐N fertilization) of both plant species was significantly increased, whereas that of large spores (>100 μm) was increased only in L. perenne plots. N fertilization resulted in a significant decrease of root colonization in L. perenne, including the AMF parameters, hyphae, arbuscules, vesicles and intensity, but not in T. repens. This phenomenon was probably caused by different C‐sink limitations of grass and legume. Lacking effects of CO2 fumigation on intraradical AMF structures (under high‐N fertilization) and no response to N fertilization of arbuscules, vesicles and colonization intensity suggest that the function of AMF in T. repens was non‐nutritional. In L. perenne, however, AM symbiosis may have amended N nutrition, because all root colonization parameters were significantly increased under low‐N fertilization, whereas under high‐N fertilization only vesicle colonization was increased. Commonly observed P‐nutritional benefits from AMF appeared to be absent under the phosphorus‐rich soil conditions of our field experiment. We hypothesize that in well‐fertilized agricultural ecosystems, grasses benefit from improved N nutrition and legumes benefit from increased protection against pathogens and/or herbivores. This is different from what is expected in nutritionally limited plant communities.
Elevated UV‐B radiation has no effect on litter quality and decomposition of two dune grassland species: evidence from a long‐term field experiment
Authors: Hoorens Bart , Aerts Rien , Stroetenga Martin
Published: December 2004

From studies on living plant tissues it has been inferred that elevated UV‐B radiation could negatively affect litter quality and subsequent decomposition. However, in general, the effects of UV‐B radiation on litter chemistry and decomposition reported in the literature are variable and are often only marginally (if at all) significant. This might be due to the ecologically unrealistic conditions under which these experiments were performed.

We investigated the effects of elevated UV‐B radiation on litter quality and subsequent decomposition on initial litter chemistry and long‐term (2 years) decomposition of freshly senescedCarex arenariaandCalamagrostis epigejosleaf litter under ecologically realistic conditions. This material was collected from a dune grassland that had received UV‐B radiation treatments for three growing seasons. It was then used in a 2‐year decomposition study using litter bags.

We found no significant effects of elevated UV‐B radiation on any of the litter chemistry parameters in either of the two species, nor did we find significant effects on litter decomposition. However, we did find significant differences in litter decomposition between the species. These differences were related to the interspecific differences in litter chemistry, particularly the litter phenolics concentration. These results show that litter quality and decomposition in dune grasslands are, also under ecologically realistic conditions, not affected by UV‐B radiation. Instead, litter decomposition is determined by constitutive interspecific differences in litter chemistry.

In conclusion, with our results added to the already existing literature, the preponderance of evidence now clearly suggests that elevated UV‐B radiation has very little, if any, impact on litter quality and subsequent decomposition in real ecosystems.
The seasonal temperature dependency of photosynthesis and respiration in two deciduous forests
Authors: Jarvis Andrew J. , Stauch Vanessa J. , Schulz Karsten , Young Peter C.
Published: December 2004

Novel nonstationary and nonlinear dynamic time series analysis tools are applied to multiyear eddy covariance CO2flux and micrometeorological data from the Harvard Forest and University of Michigan Biological Station field study sites. Firstly, the utility of these tools for partitioning the gross photosynthesis and bulk respiration signals within these series is demonstrated when employed within a simple model framework. This same framework offers a promising new method for gap filling missing CO2flux data. Analysing the dominant seasonal components extracted from the CO2flux data using these tools, models are inferred for daily gross photosynthesis and bulk respiration. Despite their simplicity, these models fit the data well and yet are characterized by well‐defined parameter estimates when the models are optimized against calibration data. Predictive validation of the models also demonstrates faithful forecasts of annual net cumulative CO2fluxes for these sites.
Climate change effects on carbon and nitrogen mineralization in peatlands through changes in soil quality
Authors: Keller Jason K. , White Jeffrey R. , Bridgham Scott D. , Pastor John
Published: December 2004

Climate change will directly affect carbon and nitrogen mineralization through changes in temperature and soil moisture, but it may also indirectly affect mineralization rates through changes in soil quality. We used an experimental mesocosm system to examine the effects of 6‐year manipulations of infrared loading (warming) and water‐table level on the potential anaerobic nitrogen and carbon (as carbon dioxide (CO2) and methane (CH4) production) mineralization potentials of bog and fen peat over 11 weeks under uniform anaerobic conditions. To investigate the response of the dominant methanogenic pathways, we also analyzed the stable isotope composition of CH4produced in the samples. Bog peat from the highest water‐table treatment produced more CO2than bog peat from drier mesocosms. Fen peat from the highest water‐table treatment produced the most CH4. Cumulative nitrogen mineralization was lowest in bog peat from the warmest treatment and lowest in the fen peat from the highest water‐table treatment. As all samples were incubated under constant conditions, observed differences in mineralization patterns reflect changes in soil quality in response to climate treatments. The largest treatment effects on carbon mineralization as CO2occurred early in the incubations and were ameliorated over time, suggesting that the climate treatments changed the size and/or quality of a small labile carbon pool. CH4from the fen peat appeared to be predominately from the acetoclastic pathway, while in the bog peat a strong CH4oxidation signal was present despite the anaerobic conditions of our incubations. There was no evidence that changes in soil quality have lead to differences in the dominant methanogenic pathways in these systems. Overall, our results suggest that even relatively short‐term changes in climate can alter the quality of peat in bogs and fens, which could alter the response of peatland carbon and nitrogen mineralization to future climate change.
Scale‐dependent climate signals drive breeding phenology of three seabird species
Authors: Frederiksen Morten , Harris Michael P. , Daunt Francis , Rothery Peter , Wanless Sarah
Published: December 2004

Breeding at the right time is essential for animals in seasonal climates in order to ensure that the energy demands of reproduction, particularly the nutritional requirements of growing young, coincide with peak food availability. Global climate change is likely to cause shifts in the timing of peak food availability, and in order to adapt successfully to current and future climate change, animals need to be able to adjust the time at which they initiate breeding. Many animals use environmental cues available before the breeding season to predict the seasonal peak in food availability and adjust their phenology accordingly. We tested the hypothesis that regulation of breeding onset should reflect the scale at which organisms perceive their environment by comparing phenology of three seabird species at a North Sea colony. As predicted, the phenology of two dispersive species, black‐legged kittiwake (Rissa tridactyla) and common guillemot (Uria aalge), correlated with a large‐scale environmental cue (the North Atlantic Oscillation), whereas a resident species, European shag (Phalacrocorax aristotelis), was more affected by local conditions (sea surface temperature) around the colony. Annual mean breeding success was lower in late years for European shags, but not for the other two species. Since correlations among climate patterns at different scales are likely to change in the future, these findings have important implications for how migratory animals can respond to future climate change.
The Negotiator and the Bomber: Analyzing the Critical Role of Active Listening in Crisis Negotiations
Authors: Royce Terry
Published: December 2004

This article extends Michael R. Hammer and Randall G. Rogan's communication‐based, interactive model of crisis negotiation by examining the role of active listening by a police negotiator in New South Wales, Australia in the process of serving a “high‐risk warrant” on an armed and dangerous man who was expected to resist. Through an analysis of the interaction between the perpetrator and the negotiator, this paper demonstrates that the use of active listening in the early stages of the negotiation was a critical factor in the resolution of this crisis and is an essential skill for any hostage negotiator.
Mediating the War of Olives and Pines: Consensus‐Based Land‐Use Planning in a Multicultural Setting
Authors: Levine Hephzibah
Published: December 2004

The proposed Nahal Tzalmon national park lies in the Galilee region of northern Israel. It encompasses land of unique natural beauty, some of which is occupied by Arab‐Israeli families. Statutory plans defining the park's boundaries were enacted more than twenty years ago. Despite ongoing preparation, however, the park has not yet opened to the public, in part because of continuous conflict between the Israeli government authorities and the resident families over property rights affecting construction, land use, and nature preservation.

In 2000, after a long period of stagnation and discord, the Joint Environmental Mediation Service ( JEMS), guided by its founding organizations — the Consensus Building Institute and the Israel–Palestine Center for Research and Information — led a mediation process in the region. This was the first such process in the history of Israeli land‐use planning. The mediation resulted in a settlement that was agreed to and signed by nearly all parties on July 8, 2004. The agreement allows residents to remain on their land and it includes incentives, such as park employment, to ensure that they help preserve the natural environment. Plans based on this agreement are currently undergoing state ratification, although several implementation challenges are yet to be resolved.

This case points to the importance of having a mediation team knowledgeable about and sensitive to local cultural norms and the difficulties of ensuring appropriate representation in the absence of a strong civic culture and organized advocacy groups. It also highlights the requisite for ensuring that all parties thoroughly understand the consensus building process and how it fits in with established bureaucratic procedures, as well as the critical need to secure strong support from implementing agencies at the outset.
Renal transplantation, immunosuppression and the skin: an update
Authors: Moloney F. J. , De Freitas D. , Conlon P. J. , Murphy G. M.
Published: December 2004

Transplant medicine has seen many innovations over past decades and continues to evolve into the 21st century. Newer immunosuppressive strategies in renal transplantation are associated with better patient and graft survival rates; however, the adverse toxicities and long‐term side effects associated with these agents present a number of challenges. Certain immunosuppressants are commonly used in dermatologic disorders, however, dermatologists may be less familiar with the clinical efficacy, side‐effect profile, and dosage of newer immunosuppressive agents. A knowledge of the molecular and cellular mechanisms of action of these agents gives us a better understanding of how these agents contribute to the cutaneous and mucosal complications frequently seen post‐transplant. With the advent of new immunosuppressive therapies and different treatment regimens, there is an increasing need for a multidisciplinary approach to balancing the risks and benefits of these medications to the individual transplant recipient. This review will highlight the different immunosuppressive agents and their effect on the skin while focusing on the evidence base to support the commonly used immunosuppressive regimes, newer protocols aimed at achieving maximum graft survival with minimal side effects, and important drug interactions with which all dermatologists should be familiar.
Chronic ultraviolet radiation modulates epidermal differentiation as it up‐regulates transglutaminase 1 and its substrates
Authors: Lee Dae‐Sung , Quan Gen , Choi Jee‐Young , Kim Soo‐Youl , Lee Seung‐Chul
Published: December 2004

Background: Ultraviolet radiation (UVR) stimulates cellular mitosis, which leads to epidermal hyperplasia. On the basis of hypothesis that chronic UVR may modulate differentiation as well as epidermal hyperplasia, we evaluated the modulation of markers of epidermal differentiation, such as transglutaminase 1 (TGase 1), filaggrin and loricrin, by chronic UVR in vivo.

Methods: Total TGase activities assay or in situ TGase activities were measured in human and mouse skin. TGase 1 expression was identified by immunohistochemical staining in human skin. In the human, the pre‐auricular skin of face was used for samples of chronic UVR, and the post‐auricular skin was selected as non‐UVR control. The changes of filaggrin and loricrin were identified by western immunoblots.

Results: In human and mouse epidermis, chronic UVR induced the increase of in situ TGase activities or total TGase activities as it up‐regulated TGase 1 expression in the epidermis. As the substrates of TGase 1, chronic UVR induced the up‐regulation of filaggrin and loricrin in mouse epidermis as well. At the same time, chronic UVR induced the marked epidermal hyperplasia in human and mouse skin.

Conclusion: Chronic UVR stimulates epidermal differentiation as it up‐regulates TGase 1 and its substrates. The modified epidermal differentiation is balanced with epidermal hyperplasia, leading to the maintenance of epidermal homeostasis in the UV‐irradiated epidermis.
Ultraviolet‐induced transformation of keratinocytes: possible involvement of long interspersed element‐1 reverse transcriptase
Authors: Banerjee Gautam , Gupta Nishma , Tiwari Jyoti , Raman Govindarajan
Published: December 2004

The normal human keratinocyte cell line, HaCaT, was transformed using multiple doses of ultraviolet (UV)A+B (UVA, 150–200 mJ/cm2 and UVB, 15–20mJ/cm2× 6). Malignant transformation was confirmed by upregulation of Cyclin D1 (mRNA) and formation of colonies on soft agar. To identify the genes involved in this transformation process, we have done rapid amplification of polymorphic DNA using RNA from unexposed and multiple‐exposed cells. Six percent PAGE showed several differentially regulated genes in exposed cells compared with unexposed cells. Total 19 genes were identified, cloned and sequenced. Three of these 19 cloned genes showed 99% homology at both DNA and protein levels to a stretch of 540 bp (180 aa) of long interspersed element (LINE)‐1 reverse transcriptase (RT) open reading frame (ORF‐2). Colonies from soft agar showed upregulation of this gene compared with non‐colonized (lawn on soft agar) cells as detected by RT‐PCR. This data implicates LINE‐1 RT (ORF‐2) in UV‐induced malignancy and can possibly be used as a marker for the diagnosis of UV‐induced skin cancer.
Ownership, Governance, and Management Issues in Small and Medium-Size Family Businesses: A Comparison of Italy and the United States
Authors: Corbetta Guido , Montemerlo Daniela
Published: December 2004

This research note reports survey results of 252 Italian family firms based on the MassMutual framework. The objectives of the survey were to analyze the structure and behavior of Italian small and medium-size family firms and compare them with those in the United States. The note focuses on these comparisons with regard to family involvement, ownership and governance structures, top management teams, decision-making processes, strategic goals, and succession perspectives. The paper goes on to explore the implications of survey results for family firms, researchers, and practitioners.
Knife Jugglers
Authors: Davenport R. John
Published: December 2004

A small slip at the cutting board can mean the difference between beautifully diced vegetables and a severed finger. An even more subtle miss might explain how one class of painkillers reduces the risk of Alzheimer's disease (AD). According to new work, the drugs nudge a cellular butcher, prodding it to dice a protein into a harmless form rather than one that clumps in the brains of AD patients. The study reveals how the painkillers alter the protein chopper and might provide a new method for identifying potential AD drugs.
Ras: The Other Pro-Aging Pathway
Authors: Longo Valter D.
Published: December 2004

Studies in worms, flies, and mice point to the insulin/insulin-like growth factor-1 (IGF-1)/phosphatidylinositol 3-kinase/Akt-like pathway as a central regulator of longevity. A similar pathway, which includes Sch9, a functional mammalian Akt/protein kinase B homolog, regulates longevity in yeast. Chronological aging in yeast is also regulated by a second pathway that includes Ras, adenylate cyclase, protein kinase A, the transcription factors Msn2 and Msn4, and Sod2. Although Ras proteins have not been implicated in longevity regulation in worms or flies, the major role of Ras in mammalian IGF-1 signaling raises the possibility that homologs of yeast Ras2 might accelerate aging in mammals. Here I review the data from experiments at both the organismal and cellular levels that support a role for Ras in the regulation of stress resistance and life span in eukaryotes.
Fanning the Flames
Authors: Davenport R. John
Published: December 2004

Some children do their chores at home but throw spitballs at school. Similarly, the enzyme telomerase helps cells by tending to the ends of their chromosomes in the nucleus, but it makes mischief elsewhere. A new study reveals that telomerase makes a second home in mitochondria--the cell's powerhouses--where it enhances damage from oxidants. The work identifies a new location for the enzyme, but further studies are necessary to illuminate how it accelerates decay.