bluuebunny/crossref_metadata_2025 huggingface dataset:
Granule cell type cerebellar hypoplasia in a beagle dog
Authors: Tago Y. , Katsuta O. , Tsuchitani M.
Published: May 2007

Cerebellar hypoplasia characterized by severe depletion of granule cells and almost intact Purkinje cells was found in a male 19-month-old beagle dog used in a toxicity study. Microscopically, there was a narrow space lacking granule cells between the row of Purkinje cells and the medulla. Gliosis was not seen in any portion of the cerebellum including this space. No significant changes were seen in the Purkinje cells except for occasional cytoplasmic vacuolation. In the molecular layer and medulla, no histopathological abnormalities were observed.
A method for sampling representative muscular venous blood during exercise in rats
Authors: Pagés T. , Fernáandez J. A. , Adán C. , Gámez A. , Viscor G. , Palacios L.
Published: May 2007

A technique for chronic cannulation of the muscular branch of the femoral vein in the rat is described. The method was validated by the application of vascular corrosion casts and comparative analysis of lactate concentration with mixed venous blood and arterial samples taken through the cannulas during lower hindlimb muscle contraction in anaesthetized rats.
Levels of alpha2 pregnancy-associated glycoprotein in maternal circulation during pregnancy in the mink
Authors: Hau J. , Andersen Lise Lotte I. , Bohn H.
Published: May 2007

This is the first demonstration of α2-pregnancy-associated glycoprotein ( α2-PAG) in the mink. Mink α2-PAG exhibits complete immunological cross reaction with dog α2-PAG when analysed in assays employing antisera against canine α2-PAG raised in rabbits. Alpha2-PAG was quantitated by rocket immunoelectrophoresis in heparin plasma samples obtained from the peripheral circulation of mink during the breeding season. The plasma levels recorded in male mink were significantly lower (23 AU/ml) than the levels recorded in females at any stage of the breeding period. Very early in the breeding season and 2 weeks after delivery the α2-PAG levels were high (>200 AU/ml) in the circulation of the female mink. Like α2-PAG in the pregnant bitch, mink α2-PAG concentrations reach a local maximum in mid-pregnancy, and a local minimum at term.
Pseudomonas aeruginosa infection in a Chinchilla lanigera
Authors: Doerning Bernard J. , Brammer David W. , Rush Howard G.
Published: May 2007

This report describes a case of Pseudomonas aeruginosa infection in a chinchilla. The affected animal displayed a variety of clinical signs including genital swelling, conjunctivitis, anorexia, weight loss, corneal and oral ulcerations and, most unusually, intradermal pustules which developed 8 days after recovery from the initial illness. The occurrence of these pustules has not been documented previously.
Influence of chronic oestrogen treatment on severity of hydronephrosis in inbred DDD mice
Authors: Mannen H. , Tsuji S. , Goto N.
Published: May 2007

It has been reported that mice treated chronically with oestrogen (oestradiol propionate) increase their bladder urine volume. Since inbred DDD mice, particularly male DDD mice, lack a protective mechanism against vesicoureteral reflux (VUR), chronic oestrogen treatment may increase the pressure in the renal pelvis and lead to severe hydronephrosis. The present studies were carried out to confirm this hypothesis. Results of a least-squares analysis of variance showed that the severity of hydronephrosis was more severe after treatment with high doses of oestrogen (1·0 and 5·0 mg/kg/week) in entire and castrated male DDD mice. Hydroureter was also observed in the same groups. Intra-vesicular pressure was 7 to 12 cmH2O higher in mice of these groups than in control DDD mice. High doses of oestrogen had no effect on the kidneys of C57BL/6 mice which showed normal protection against VUR, though it increased bladder urine volume. These findings support the hypothesis that hydronephrosis in DDD mice is caused by an incomplete protective mechanism against VUR.
Genetic variation within and between strains of outbred Swiss mice
Authors: Cui Shuliang , Chesson Clive , Hope Rory
Published: May 2007

The aim of this survey was to measure levels of genetic variation within and between 5 different strains of outbred Swiss mice. Ten to 15 animals from each strain (NIH, Q(S), ARC, IMVS and STUD) were typed, using allozyme electrophoresis, at 10 gene loci: Mod-1, Idh-1, Gpi-1, Es-1, Es-3, Hbb, Pep-3, Gr-1, Got-2 and Pgm-1. Polymorphic variation in at least one of the 5 strains was detected at all 10 loci. The proportion of polymorphic loci ranged from 0·3 (NIH) to 0·8 (IMVS) with a mean of 0·52. Average expected heterozygosities ranged from 0·08 (NIH) to 0·37 (IMVS) with a mean of 0·21. The inbred strain SWR was, as expected, homozygous at all 10 loci. The amount of allelic substitution between pairs of strains was quantified using Nei's genetic distance, and a dendrogram based on these genetic distances showed a close overall similarity in its branching pattern to the known genealogy of the strains. This survey showed that a considerable degree of genetic variation persists in the 5 strains examined, a level of variation similar to that previously detected by Rice and O'Brien (1980) in 3 other outbred Swiss strains.
Comparison of gavage, water bottle, and a high-moisture diet bolus as dosing methods for quantitative D-xylose administration to B6D2F1 (Mus musculus) mice
Authors: Zimmer J. Paul , Lewis Sherry M. , Moyer Jerry L.
Published: May 2007

Gavage, water bottle, and diet incorporation are 3 dosing methods used orally to administer test compounds to rodents. These 3 methods were compared in mice to determine which represented the most quantitative delivery system. For dietary incorporation, a highmoisture bolus form of NIH-31 rodent meal was developed using hydroxypropyl methylcellulose as an autoclave-stable binding agent. A highmoisture bolus was selected to increase the acceptability of the dosed diet and to promote quantitative consumption through reduced wastage. The test compound used was D-xylose, a pentose sugar that may be quantitatively detected, colorimetrically, in urine following oral dosing. Six male and 6 female B6D2F1 mice were placed in metabolism cages and dosed with a known quantity of D-xylose by each of the 3 methods. Urine was collected before and after each method of administration and analysed for total D-xylose; the per cent recovery was based upon the amount of D-xylose consumed. Quantitative consumption was apparently greatest for water bottle dosing with an average recovery of 56·0% of the original D-xylose dose. High-moisture bolus incorporation ranked second with 50·0% D-xylose recovery, and gavage was third with 41·0% D-xylose recovery.
Murine cage density: cage ammonia levels during the reproductive performance of an inbred strain and two outbred stocks of monogamous breeding pairs of mice
Authors: Eveleigh J. R.
Published: May 2007

The Laboratory Animal Breeders Association guidelines recommend a minimum floor area of 300 cm2 for a monogamous pair of inbred/outbred mice or a trio of inbreds. The mean level of ammonia produced during lactation from BALB/c, TO and CD-1 breeding pairs housed in M2 cages with a floor area of 300 cm2 on Day 4 after cleaning was 30 ppm, 87 ppm and 92 ppm, respectively. All 3 strains of mice, particularly the outbred strains, were subjected to high levels of ammonia as compared with human long-term health and safety occupational exposure limits (25 ppm). However, there is a gradient of ammonia within an M2 breeding cage from the nest (19 ppm), to the food hopper, 77 ppm. By housing CD-1 pairs of mice in RM2 cages which have more than double the floor area of M2 cages (676 cm2), the mean level of ammonia during lactation on Day 4 after cleaning was reduced to 26 ppm. The reproductive performance on inbred/outbred strains of mice has to be equated with cage size (floor area) to maintain acceptable levels of ammonia. It is suggested that the recommended minimum floor areas for breeding mice be reviewed.
Intestinal, segmented, filamentous bacteria in a wide range of vertebrate species
Authors: Klaasen H. L. B. M. , Koopman J. P. , Van Den Brink M. E. , Bakker M. H. , Poelma F. G. J. , Beynen A. C.
Published: May 2007

Segmented, filamentous bacteria (SFBs) form a group of bacteria with similar morphology and are identified on the basis of their morphology only. The relationships of these organisms are unclear as the application of formal taxonomic criteria is impossible currently due to the lack of an in vitro technique to culture SFBs. The intestine of laboratory animals such as mice, rats, chickens, dogs, cats and pigs is known to harbour SFBs. To see whether this extends to other animal species, intestines from 18 vertebrate species, including man, were examined. SFBs were detected with light microscopy in the cat, dog, rhesus monkey, crab-eating macaque, domestic fowl, South African claw-footed toad, carp, man, laboratory mouse and rat, wood mouse, jackdaw and magpie. These results suggest that non-pathogenic SFBs are ubiquitous in the animal kingdom. Among apparently identical animals, there was considerable variation in the degree of SFB colonization. It is suggested that SFB colonization could serve as a criterion of standardization of laboratory animals.
Local metabolic, pathophysiological and histological changes in venous ulcers
Authors: Maksimović Ž , Maksimović M
Published: May 2007

Objectives: The pathogenesis of venous ulceration is not completely understood. The aim of this research was to measure and compare various parameters in ulcers caused by abnormalities in superficial venous (SU) versus deep venous flow (DU), to determine possible differences in their pathogenesis.

Methods: Analysis of venous blood gases and levels of anaerobic metabolites from the ulcer site were measured in SU ( n = 8) and DU patients ( n = 8) and compared with control samples from the contralateral healthy limb. Histological examination via electron microscopy was also performed in tissue samples from the ulcer sites in SU ( n = 2) and DU ( n = 2) patients.

Results: The SU group had significantly lower values of partial oxygen pressure (pO2) and oxygen saturation (sO2), and significantly higher values of partial pressure of carbon dioxide, bicarbonate concentration and total carbon dioxide versus control samples. The DU group had significantly higher values of pO2 and sO2 versus controls. Elevated levels of pyruvate ( P < 0.01) and lactate ( P < 0.05) were found in DU ulcer blood samples taken after 30 min of passive standing (static shear), as compared with control blood samples. However, no significant histological differences between SU and DU samples could be distinguished via electron microscopy.

Conclusions: Differences in levels of venous blood gases and anaerobic metabolites indicate a potential difference in the causation and development of superficial versus deep venous caused ulcers. This may have clinical significance for the diagnosis and treatment of these conditions.
Subfascial endoscopic perforator vein surgery using balloon dissector and saphenous vein surgery in chronic venous insufficiency
Authors: Uncu H
Published: May 2007

Objectives: Subfascial endoscopic perforator vein surgery (SEPS) has recently been a popular alternative to classical surgical methods in the treatment of severe venous insufficiency of the lower extremity. Yet, there are not many reports concerning this less invasive operation, and many modified methods are applied. We would like to report the clinical results of our country's first SEPS operations performed by using balloon dissector.

Methods: The SEPS via two ports and using balloon dissector with saphenous vein stripping and phlebectomy in patients with severe venous insufficiency. Pneumatic tourniquet has never been applied.

Results: Twenty-eight operations were performed on 28 patients (13 female, 15 male). Active open ulcers were present in four legs, ulcer scars were present in two patients, skin changes were present in 12 legs and severe oedema was present in 10 legs. An improvement in all clinical findings and complaints was determined following the operations. A significant drop was determined in chronic venous insufficiency scores. No serious complication requiring rehospitalization of the patients was observed. All the patients were followed up for six months, and none presented again with any complaints.

Conclusion: SEPS using balloon dissector with saphenous vein surgery we performed is an effective, reliable and promising method.
The diagnostic value of light reflection rheology for suspected deep vein thrombosis: a five-and-a-half year single centre experience
Authors: Smith R A , Rosser S , de Cossart L M
Published: May 2007

Objectives: Previous studies evaluating light reflection rheology (LRR) in the preliminary diagnosis of suspected deep vein thrombosis (DVT) have been based on limited patient numbers. The objective of this study was to demonstrate the diagnostic value of LRR in this setting for a large patient series.

Methods: A retrospective study was carried out using prospectively collected data over a five-and-a-half year period. During the study period, 3342 limbs were assessed with LLR in 3105 patients referred with suspected DVT (both inpatients and outpatients).

Results: In total, 2396 (71.7%) of all the LRR tests carried out yielded an abnormal result. Of the remaining 946 (28.3%) with a normal result, 204 went on to have a duplex scan due to a high clinical index of suspicion, and 14 DVTs were identified on duplex scanning. Of the remaining 742 patients with a normal LRR result who were not scanned, six re-presented within three months with a confirmed DVT, and one with a confirmed pulmonary embolus (PE). These results yield a negative predictive value of 97.8%, a sensitivity of 96.4% with a three-month post-test thromboembolism incidence of 0.9%. Use of LRR allowed duplex scanning to be avoided for 22.2% of referrals.

Conclusions: Despite the increasing use of D-dimers and clinical probability scoring in the preliminary investigation of thromboembolic events, LRR remains a viable alternative in safely risk-stratifying patients with suspected DVT.
Pelvic congestion syndrome: chronic pelvic pain caused by ovarian and internal iliac varices
Authors: Liddle A D , Davies A H
Published: May 2007

Chronic pelvic pain is a common and disabling condition affecting women of childbearing age. A specific diagnosis for the condition is often difficult, and referred pain from the abdominal viscera, neurogenic and psychogenic factors have all been implicated, as have pelvic conditions such as endometriosis, pelvic inflammatory disease and ovarian cysts; no diagnosis is made in 60% of patients. Pelvic congestion syndrome (PCS), the presence of varices of the pelvic veins, has been shown to be the underlying aetiology in a significant proportion of patients with chronic pelvic pain; the development of these varices is caused by a combination of endocrine and mechanical factors. Given the positional nature of these varices, they are rarely diagnosed with conventional methods such as B-mode ultrasound and diagnostic laparoscopy. Diagnosis is best made with selective ovarian venography, although newer, non-invasive methods such as magnetic resonance imaging and duplex ultrasound are increasingly gaining favour. Pelvic varices are eminently treatable, either using ovarian suppression or by the ligation or embolization of the pelvic veins.
Communicating Doppler-derived information in superficial venous surgery
Authors: Oinonen A , Lehtola A , Sugano N , Albäck A , Lepäntalo M
Published: May 2007

Objective: The aim was to evaluate how Doppler-derived information could be communicated in written form to surgeons before superficial vein surgery.

Patients and methods: The study included 78 patients with 102 limbs operated on for C2–4 superficial venous insufficiency. A vascular surgeon, in a vascular reference centre, preoperatively examined all patients with duplex ultrasound or hand-held Doppler and prepared a treatment plan accordingly. The plan was then sent to operative units. Patients were cohorted and operated on in two groups either with or without preoperative Doppler marking. At two years postoperatively, an independent examiner performed a follow-up duplex examination.

Results: Elimination of preoperatively identified axial reflux succeeded better in preoperatively marked than in non-marked group: axial reflux sites in saphenofemoral junction (SFJ), great saphenous vein (GSV), main branches of GSV or small saphenous vein (SSV) remained in five vs. 12 limbs (10 vs. 26%, P = 0.063). Overall, some axial reflux remained in 11 vs. 21 limbs (22 vs. 41%, P = 0.033).

Conclusion: Preoperative Doppler-derived information was not communicable in written form. Thus, it is important for the operating surgeon to do ultrasound-based preoperative marking allowing him to perform more accurate surgery.
The venous valve agger and plasma noradrenaline-mediated venodilator feedback
Authors: Crotty T P
Published: May 2007

Objective: To investigate the structure and function of the venous valve agger, a fibroelastic structure located at the base of every valve in veins that are responsive to noradrenaline (NA).

Design: Constant flow perfusion studies of the responses of in situ and in vitro canine lateral saphenous vein segments to NA and electrical stimulation, supplemented by histological studies of the segments.

Setting: University Departments of Physiology and Histology.

Materials: Segments of canine lateral saphenous vein. In vitro = 84, in situ = 60 plus.

Results: The agger is a crescentic fibroelastic sleeve, spanning the vein wall very obliquely through which the local vasa venarum network drains. It has a dedicated musculature which, when the tone rises, contracts and stretches the fibroelastic of the agger and opens the drainage channels to reflux. Each agger has four muscles, two each of which insert on the concave and convex margins of the agger. They pull in opposite directions when they contract.

Conclusions: The agger forms part of a complex that, in conjunction with its dedicated musculature, a reversible transmural pressure gradient and physiological turbulence in the valve sinuses, positively facilitates drainage from the local segment of the vasa venarum network when venous tone is normal; and when venous tone is elevated it pumps and sucks blood from the lumen of the vein to perfuse the vasa venarum network. When the plasma NA in the perfusate diffuses from the network, it causes a localized venodilator feedback effect that restores the elevated tone of the vein to normal. The feedback effect is potent, being estimated to reduce the venonstrictor effect of neuronal NA by about 50% when flow is laminar and considerably more when flow is turbulent. There is evidence that plasma NA may constitute the lateral inhibitory component of the NA chemostimulus of the smooth muscle cell, neuronal NA constituting the excitor component. A chronic breakdown in agger function is believed to be the cause of varicose veins.
Grazing Angle Attenuated Total Reflection Spectroscopy: Fields at the Interface and Source of the Enhancement
Authors: Milosevic Milan , Milosevic Violet , Berets S. L.
Published: May 2007

With the tremendous growth in the semiconductor and coatings industries, spectroscopic methods of examining extremely thin films on high refractive index substrates have become increasingly important. One infrared method for analyzing monolayers on substrates such as silicon and gold that has recently gained popularity is ‘grazing’ or high angle of incidence attenuated total reflection (ATR) spectroscopy. This paper investigates the directional electric field strengths and the extraordinary sensitivity achieved by using the grazing angle ATR method for analyzing monolayers on silicon substrates.
A Probability-Based Spectroscopic Diagnostic Algorithm for Simultaneous Discrimination of Brain Tumor and Tumor Margins from Normal Brain Tissue
Authors: Majumder Shovan K. , Gebhart Steven , Johnson Mahlon D. , Thompson Reid , Lin Wei-Chiang , Mahadevan-Jansen Anita
Published: May 2007

This paper reports the development of a probability-based spectroscopic diagnostic algorithm capable of simultaneously discriminating tumor core and tumor margins from normal human brain tissues. The algorithm uses a nonlinear method for feature extraction based on maximum representation and discrimination feature (MRDF) and a Bayesian method for classification based on sparse multinomial logistic regression (SMLR). Both the autofluorescence and the diffuse-reflectance spectra acquired in vivo from patients undergoing craniotomy or temporal lobectomy at the Vanderbilt University Medical Center were used to train and validate the algorithm. The classification accuracy was observed to be approximately 96%, 80%, and 97% for the tumor, tumor margin, and normal brain tissues, respectively, for the training data set and approximately 96%, 94%, and 100%, respectively, for the corresponding tissue types in an independent validation data set. The inherently multi-class nature of the algorithm facilitates a rapid and simultaneous classification of tissue spectra into various tissue categories without the need for a hierarchical multi-step binary classification scheme. Further, the probabilistic nature of the algorithm makes it possible to quantitatively assess the certainty of the classification and recheck the samples that are classified with higher relative uncertainty.
Near-Infrared Spectroscopic Method for Real-Time Monitoring of Pharmaceutical Powders during Voiding
Authors: Barajas Martha J. , Cassiani Alex Rodriguez , Vargas Wandylis , Conde Carlos , Ropero Jorge , Figueroa Jorge , Romañach Rodolfo J.
Published: May 2007

A near-infrared (NIR) spectroscopic method has been developed to monitor flowing pharmaceutical powders during their voiding and detect post-blending segregation. The method is capable of providing both chemical and physical information (particle size differences) on the flowing pharmaceutical powders. Particle size differences are widely recognized as the predominant driver for segregation. Pharmaceutical powders may segregate following blending as they are voided down pipes to compressing machines, increasing the variability of the drug content and dissolution of the final product tablets because of segregation. NIR diffuse reflectance spectra of pharmaceutical powders were obtained following voiding through a six-foot pipe. Spectral subtraction was used to eliminate baseline differences but maintain particle size differences. The NIR spectra indicated differences in the particle size of the flowing powder. Particle size differences were also tracked throughout the voiding of pharmaceutical powders by plotting the absorbance at 1536 nm. The method was also applied to the voiding of two layers of lactose particles with different particle sizes. The system described in this report provides an approach to study post-blending segregation in pharmaceutical powders and other relevant materials.
In Situ Analytical Assessment and Chemical Imaging of Historical Buildings Using a Man-Portable Laser System
Authors: Fortes F. J. , Cuñat J. , Cabalín L. M. , Laserna J. J.
Published: May 2007

In this work, the capability of laser-induced breakdown spectrometry for the in situ analytical assessment and chemical mapping of the façade of the cathedral of Malaga (Spain) has been demonstrated. The task required the use of a portable laser analyzer that allowed real-time spectral acquisitions in the field. A man-portable laser, based on a Q-switched Nd:YAG laser operating at its fundamental wavelength, has been utilized to generate a LIBS plasma of the sample surface. A chemical characterization of the different materials employed in the construction of this building has been performed. The purpose of this study was to use LIBS spectrochemical analysis to qualitatively discriminate between sandstone, limestone, marble, and cement mortar, which are the main components used in this class of historical monument. The field analysis was performed in two zones: the northern façade and the “girola”; the total areas of analysis of the two regions were 250 m2 and 650 m2, respectively. Chemical images of Si/Ca and Ca/Mg ratios from both parts of the building were generated. During the measurement campaign, a protocol of analysis was chosen so as to achieve an accurate description of the building materials with respectable spatial resolutions.
Reproducible Surface-Enhanced Raman Scattering Spectra of Bacteria on Aggregated Silver Nanoparticles
Authors: Kahraman Mehmet , Yazici M. Müge , Slahin Fikrettin , Bayrak Ömer F. , Çulha Mustafa
Published: May 2007

Surface-enhanced Raman scattering (SERS) is proven to be a powerful technique for rapid identification and discrimination of microorganisms. However, due to the heterogeneous nature of the samples, the acquisition of reproducible spectra hinders the further development of the technique. In this study, we demonstrate the influence of the experimental conditions on SERS spectra. Then, we report a simple sample preparation method coupled with a light microscope attached to a Raman spectrometer to find a proper spot on the sample to acquire reproducible SERS spectra. This method utilizes the excited surface plasmons of the aggregated silver nanoparticles to visualize the spots on the sample. The samples are prepared using the concentrated silver colloidal solutions. The collection time for one spectrum is 10 s and each spectrum is a very good representative of the other spectra acquired from the same sample. The nature of the surface charge of the silver nanoparticles influences the spectral features by determining the strength of the interactions between nanoparticles and bacteria and the aggregation properties of the nanoparticles. Although increasing the colloid concentration in the sample resulted in reproducible spectra from arbitrary points on the sample, a great variation from sample to sample prepared with the different colloidal solution concentrations is observed.
Laser Diagnostics of Welding Plasma by Polarization Spectroscopy
Authors: Lucas Owen , Alwahabi Zeyad T. , Linton Valerie , Meeuwissen Karel
Published: May 2007

The application of polarization spectroscopy (PS) to detect atomic species in an atmospheric pressure welding plasma has been demonstrated. PS spectra of Na atoms, seeded in the shielding gas flow of a gas tungsten arc welding (GTAW) plasma, are presented at different pump beam energies. The nature of the PS technique was found to be very efficient in suppressing the high background emission associated with the welding plasma. The PS spectral profiles appear to be Lorentzian and Lorentzian cubed for high and low pump beam energy, respectively. The effect of beam steering, due to the thermal gradient in the interaction plasma zone, was addressed. It was found that there is 2% unavoidable error in the detectable PS signal.
Applicability of Fiber-Optic-Based Raman Probes for On-Line Reaction Monitoring of High-Pressure Catalytic Hydrogenation Reactions
Authors: Hamminga Gerben M. , Mul Guido , Moulijn Jacob A.
Published: May 2007

This study evaluates the applicability of fiber-optic-based Raman probes for on-line reaction monitoring of high-pressure catalytic hydrogenation reactions in batch autoclaves. First, based on trends in the strong intensity of the 945 cm−1 C–O–C vibration of 1,3-dioxolane, the effect of various experimental parameters on sensitivity was evaluated and can be summarized as follows: (1) above 500 rpm a linear increase in stirring speed induces a linear decrease in Raman intensity; (2) a linear increase in hydrogen pressure also leads to a linear decrease of the Raman signal; (3) linear temperature elevation exponentially decreases the Raman intensity; and (4) increasing the catalyst particle concentration results in a steep nonlinear decrease of the Raman signal. Light scattering by gas bubbles, or combined scattering and absorption by (black) catalyst particles, reducing the amount of light collected by the optical fiber probe, explain the observed experimental trends. Second, the sensitivity of Raman spectroscopy was directly compared with attenuated total reflection–Fourier transform infrared (ATR-FT-IR) spectroscopy in the analysis of three different hydrogenation reactions over a Cu–ZnO catalyst. From the applied target molecules, diethyl maleate hydrogenation could be very well analyzed by Raman spectroscopy due to the high Raman scattering efficiency of the C=C bond, while for analysis of the hydrogenation of γ-butyrolactone or 1-butanal, ATR-FT-IR is the technique of choice.
Blank Augmentation Protocol for Improving the Robustness of Multivariate Calibrations
Authors: Kramer Kirsten E. , Small Gary W.
Published: May 2007

An updating procedure is described for improving the robustness of multivariate calibration models based on near-infrared spectroscopy. Employing a single blank sample containing no analyte, repeated spectra are acquired during the instrumental warm-up period. These spectra are used to capture the instrumental profile on the analysis day in a way that can be used to update a previously computed calibration model. By augmenting the original spectra of the calibration samples with a group of spectra collected from the blank sample, an updated model can be computed that incorporates any instrumental drift that has occurred. This protocol is evaluated in the context of an analysis of physiological levels of glucose in a simulated biological matrix designed to mimic blood plasma. Employing data of calibration and prediction samples acquired over approximately six months, procedures are studied for implementing the algorithm in conjunction with calibration models based on partial least squares (PLS) regression. Over the range of 1–20 mM glucose, the final algorithm achieves a standard error of prediction (SEP) of 0.79 mM when the augmented PLS model is applied to data collected 176 days after the collection of the calibration spectra. Without updating, the original PLS model produces a seriously degraded SEP of 13.4 mM.
Temperature-Controlled Confocal Raman Microscopy to Detect Phase Transitions in Phospholipid Vesicles
Authors: Fox Christopher B. , Myers Grant A. , Harris Joel M.
Published: May 2007

Optical-trapping confocal Raman microscopy enhances the capabilities of traditional Raman spectroscopy for the analysis of small particles by significantly reducing the sampling volume and minimizing background signal from the particle surroundings. Chemical composition and structural information can be obtained from optically trapped particles in aqueous solution without the need for labeling or extensive sample preparation. In this work, the challenges of measuring temperature-dependent changes in suspended particles are addressed with the development of a small-volume, thermally conductive sample cell attached to a temperature-controlled microscope stage. To demonstrate its function, the gel to liquid-crystalline phase transitions of optically trapped lipid vesicles, composed of pure 1,2-ditridecanoyl- sn-glycero-3-phosphocholine (DTPC), 1,2-dimyristoyl- sn-glycero-3-phosphocholine (DMPC), and 1,2-dipalmitoyl- sn-glycero-3-phosphocholine (DPPC), were detected by changes in Raman spectra of the lipid bilayer. The Raman scattering data were found to correlate well with differential scanning calorimetry (DSC) results.
On the Behavior of Indole-Containing Species Sequestered within Reverse Micelles at Sub-Zero Temperatures
Authors: Munson Chase A. , Kelepouris Lee , Baker Gary A. , Baker Sheila N. , Blanchard Gary J. , Bright Frank V.
Published: May 2007

We report on the effects of temperature (+30 to −100 °C) on the fluorescence from N-acetyl tryptophanamide (NATA) and human serum albumin (HSA) sequestered within Aerosol-OT (AOT) reversed micelles. NATA reports simultaneously from the polar and non-polar side of the reverse micelle interface. As the sample temperature decreases, the relative fraction of NATA molecules associated with the polar side increases. This redistribution process is characterized by ΔH = −14.8 ± 0.6 kJ/mol and ΔS = −54 ± 2 J/(K mol). The activation energy for thermal quenching ( Ea,TQ) associated with the polar side NATA molecules is 6.7 kJ/mol before the micelles have shed water and 1.0 kJ/mol after water shedding (below approximately −20 °C). The time-resolved fluorescence intensity decay for tryptophan-214 in HSA is triple exponential. We suggest that these lifetimes arise from three indole residue conformations in equilibrium. Cooling the sample causes a freezing-in of the least quenched conformer; the other conformers are frozen out. The Ea,TQ value for the shortest lifetime component is 6 kJ/mol. The Ea,TQ for the long and intermediate lifetime components are equivalent (∼1.5 kJ/mol).
Background-Free Coherent Anti-Stokes Raman Scattering of Gas- and Liquid-Phase Samples in a Mesoporous Silica Aerogel Host
Authors: Konorov Stanislav O. , Turner Robin F. B. , Blades Michael W.
Published: May 2007

Efficient time-resolved coherent anti-Stokes Raman scattering (CARS) of atmospheric nitrogen and ethanol trapped in a nanoporous silica aerogel matrix is demonstrated. Silica aerogel hosts are attractive for analytical CARS spectroscopy due to their high porosity/low density, low refractive index, and low scattering cross-section. Differences between the resonant and nonresonant parts of the nonlinear optical susceptibilities lead to much longer relaxation times for analytes compared to the matrix. Time-resolved CARS can then be used to obtain a nearly background-free measurement at characteristic vibrations of the analyte. These results demonstrate the potential of this approach for rapid, sensitive, background-free analyses of analytes entrapped in the aerogel pores, which may be advantageous for some environmental, chemical, and biological sensing applications.
Infrared—Ultraviolet Sum-Frequency Generation Spectrometer with a Wide Tunability of the Ultraviolet Probe
Authors: Maeda Toshiki , Ishibashi Taka-Aki
Published: May 2007

We have constructed a multiplex infrared–ultraviolet (IR-UV) sum-frequency generation (SFG) spectrometer that has a wide tunable range (235–390 nm) of the UV probe wavelength. The tunable UV probe was obtained by doubling the signal output of an optical parametric amplifier pumped by a 400 nm picosecond pulse. A prism monochromator was used as a tunable sharp-cut bandpass filter to reduce stray light due to the scattering of the UV probe so that any wavelength within the tunable range can be chosen as that of the UV probe. The SFG spectra of p-mercaptobenzoic acid on a gold substrate was measured with 289 and 334 nm UV probes. The SFG vibrational band intensities due to the carbonyl stretch mode and a phenyl ring stretch mode measured with the 289 nm probe were approximately three times larger than those measured with the 334 nm probe. The enhancement was ascribed to an electronic resonant effect.
Use of Polarized Spectroscopy as a Tool for Examining the Microstructure of Cellulosic Textile Fibers
Authors: Garside Paul , Wyeth Paul
Published: May 2007

Textile artifacts form a vital part of our cultural heritage. In order to determine appropriate methods of conservation, storage, and display, it is important to understand the current physical state of an artifact, as effected by the microstructure of the component fibers. The semi-crystalline nature of the constituent polymer aggregates, the degree of crystallinity, and the crystallite orientation have a significant influence on mechanical properties. The value of polarized Fourier transform infrared (FT-IR) spectroscopy in probing these aspects of cellulosic fibers has been assessed. A variety of representative fibers (both natural plant fibers and regenerated materials) were examined by polarized attenuated total reflection spectroscopy (Pol-ATR) and polarized infrared microspectroscopy (Pol-μIR); the former is a surface sampling technique and the latter is a transmission technique. The introduction of a polarizer into the system allows the alignment as well as the nature of bonds to be determined, and thus the presence and extent of crystallinity or long-range ordering can be investigated. Using the data from the Pol-ATR experiments, it was found to be possible to derive the principle alignment of the cellulose polymer with respect to the fiber axis, along with an indication of the total cellulose crystallinity of the material, as measured by a crystallinity parameter, χ. The Pol-μIR spectra, on the other hand, yielded more limited information, particularly when considering plant fibers with more complex microstructures.
On-Line Recalibration of Spectral Measurements Using Metabolite Injections and Dynamic Orthogonal Projection
Authors: Dabros Michal , Amrhein Michael , Gujral Paman , von Stockar Urs
Published: May 2007

Spectrometers are enjoying increasing popularity in bioprocess monitoring due to their non-invasiveness and in situ sterilizability. Their on-line applicability and high measurement frequency create an interesting opportunity for process control and optimization tasks. However, building and maintaining a robust calibration model for the on-line estimation of key variables of interest (e.g., concentrations of selected metabolites) is time consuming and costly. One of the main drawbacks of using infrared (IR) spectrometers on-line is that IR spectra are compromised by both long-term drifts and short-term sudden shifts due to instrumental effects or process shifts that might be unseen during calibration. The effect of instrumental drifts can normally be reduced by referencing the measurements against a background solution, but this option is difficult to implement for single-beam instruments due to sterility issues. In this work, in order to maintain the robustness of calibration models for single-beam IR and to increase resistance to process and instrumental drifts, planned spikes of small amounts of analytes were injected periodically into the monitored medium. The corresponding measured difference spectra were scaled-up and used as reference measurements for updating the calibration model in real time based on dynamic orthogonal projection (DOP). Applying this technique led to a noticeable decrease in the standard error of prediction of metabolite concentrations monitored during an anaerobic fermentation of the yeast Saccharomyces cerevisiae.
Chemical Imaging of Latent Fingerprint Residues
Authors: Ricci Camilla , Phiriyavityopas Phiraporn , Curum Nicholas , Chan K. L. Andrew , Jickells Sue , Kazarian Sergei G.
Published: May 2007

In situ attenuated total reflection Fourier transform infrared (ATR-FT-IR) spectroscopic imaging has been used to obtain chemical images of fingerprints under controlled humidity and temperature. The distribution of lipid and amino acid components in the fingerprints from different donors left on the surface of the ZnSe crystal has been studied using an in situ FT-IR spectroscopic imaging approach under a controlled environment and studied as a function of time. Univariate and multivariate analyses were employed to analyze the spectroscopic dataset. Changes in the spectra of lipids with temperature and time have been detected. This information is needed to understand aging of the fingerprints. The ATR-FT-IR spectroscopic imaging offers a new and complementary means for studying the chemistry of fingerprints that are left pristine for further analysis. This study demonstrates the potential for visualizing the chemical changes of fingerprints for forensic applications by spectroscopic imaging.
Applied Spectroscopy News
Authors: Hellgeth John W.
Published: May 2007

Applied Spectroscopy News is a monthly feature in the journal. It includes information from the Society for Applied Spectroscopy, news from other societies and institutions, announcements of meetings, schools, or other activities, and reports of symposia from recent conferences. If you have news items, a meeting announcement, or a report from a symposium that would be of interest to readers of Applied Spectroscopy, contact Deborah K. Bradshaw, Applied Spectroscopy News Editor, P.O. Box 536307, Orlando, Florida 32853-6307, e-mail: 70454.151@compuserve.com , Ph: (407) 898-3823.
Pistes pour une gestion décentralisée des ressources forestières au Mali | Towards a decentralised management of forest resources in Mali
Authors: Cuny Pascal , Buttoud Gérard
Published: May 2007

The promotion of decentralised local management of forest resources does not always take the interests and capacities of individuals and local institutions into account. Nevertheless, despite a diversity of character, they represent the potentially strategic groups involved in specific forest actions. Their intervention, based on the complementary nature, leads one to suppose that a move towards communal forest management is possible within a global management framework of the inevitable conflicts of interest between actors and the search for a balance between informal and formal regulations.
Governance in der Waldwirtschaft | Governance in forest economy
Authors: Hostettler Martin
Published: May 2007

The Swiss forest economy has been trying for many years to improve logistics in the chain of the added value of wood. This work addresses necessary reforms to the system within the context of new institutional economics. The basic concept is explained, transaction costs of markets and hierarchies are presented systematically and the forms of governance structures outlined. The example of Swiss forest economy shows that fruitful points of departure can be developed aimed at reforming the vertical and horizontal relations between enterprises, as well as internal questions of governance. A pre-condition to achieve more efficient governance in forest economy is the reduction of restrictive institutions, whether formal or informal.
Prime valutazioni sull'introduzione della rinnovazione naturale nel bosco ceduo di castagno misto a faggio nella foresta sperimentale e didattica della SPF di Zurigo a Novaggio, Cantone Ticino | Preliminary evaluation of the introduction of natural regeneration into a chestnut-beech coppice in Novaggio, Tessin, Switzerland
Authors: Ott Ernst , Conceprio Fabrizio , Pedrini Andrea
Published: May 2007

To date there has been very little information on the dry deciduous forests on the southern side of the alps. To redress this imbalance we carried out an intensive and detailed survey of the natural regeneration processes in chestnut-beech-coppice stands in a deciduous forest over a period of 6 years. On a steep sunless slope with easterly exposure we clear cut four narrow aisles, each about 15 metres wide and 100 metres long. On numerous transsections within these aisles, all the way up to the borders where trees were left standing, we installed 119 test sample areas of 1m2, systematically and objectively distributed. The regular examination and taking stock of initial rich natural seeding shows very clearly that this abundance was made possible, above all, by the roughening up of the top soil during clearing. In the following years nearly all test sample areas were covered with increasingly thick layers of leaf-mould which appears to have made subsequent seeding amazingly difficult. In fact, numerous specialist publications and surveys confirm that thick organic cover (the accumulation of leaves over many years with the subsequent formation of leaf-mould)on locations with frequent and severe risk of dehydration is especially unfavourable to germination substrate. However,once the seedlings have successfully put down roots the risk of mortality is strongly diminished in the presence of adequate light.

In order to foster natural regeneration in these dry deciduous forest stands we recommend that following procedures be implemented. Using a uniform shelterwood compartment system,the very first light felling (opening up of the stand) should be carried out in winter immediately after effective seeding and the top soil should be roughened up, at least in some places, down to the level of mineral earth layers. Felling carried out in the traditional manner is usually enough to ensure that the top soil is roughened up and, in addition, that seeds and mineral earth are mixed.

The increase in the amount of light should optimised in such a way as to allow, on the one hand, regeneration seedlings to survive and grow, but that does not heighten competition from the development of vegetation and possible shoots on the other.

Our examination produced further results: growth and survival of the regeneration depends on the amount of light, regeneration reserve under the previous old stand, as well as on the strong throttling of development of the vegetation and shoots in the narrow aisles with little sunlight.
Untersuchungen über den immergrünen Buchsbaum (Buxus sempervirens L.) in Nordwestanatolien (Türkei): ein Beitrag zur Erhaltung der biologischen Artenvielfalt und zum Naturschutz | Examination of box (Buxus sempervirens L.) in Northwest Anatolia, Turkey: a contribution for the preservation of biological diversity and nature conservation
Authors: Çolak Alper H.
Published: May 2007

The occurrence of stands of box, which originally grew in many areas, was reduced in Turkey due to anthropogenic influences. In order to enhance our scientific knowledge of this species we carried out ecological, biological and silvicultural examinations. Following these examinations, we were able to assign box into K strategic class and using the knowledge gained we worked out the prerequisites for the realisation of nature conservation and tending measures.
Die Verbreitung und die waldbauliche Bedeutung der Weisstanne in den Zwischenalpen. Ein Beitrag für die waldbauliche Praxis | The distribution and silvicultural consequences of silver fir in alpine regions. A contribution to silvicultural practices
Authors: Frey Hans-Ulrich
Published: May 2007

The areas where silver fir occurs in Switzerland are divided into main, minor or relict areas. In the main areas a wide distribution of silver fir is to be reckoned with. In contrast to traditional systems the emphasis of silver fir distribution lies somewhat lower and more clearly in pre-alpine regions. In the minor areas silver fir has withdrawn to shadowy slopes and is limited to low-lying valleys between the alps. In main valleys where the altitude of the valley bottom is higher than 1000 m.a.s.l. the current presence of silver fir is considered to be a relict of a postglacial warm period, favourable to silver fir, and not the result of human destruction.
Vierzig Jahre permanente Stichprobeninventuren in der Schweiz | Forty years of permanent inventory sampling in Switzerland's forests
Authors: Bachmann Peter
Published: May 2007

Permanent sampling procedures were introduced into Swiss Forestry Management around forty years ago. Discussions arising from two of six talks (from P. Brassel and M. Zobeiry) presented at a Monday Colloquium devoted to this theme at the ETH Zurich are summarised. The successful Swiss National Forest Inventory, which has been carried out twice so far, is based on permanent earth samples, and supplemented with aerial surveys. For financial reasons, the planned third survey will only comprise one repetition of the second sampling with a few additions to the catalogue of characteristics. In the natural forests of northern Iran permanent sampling has been carried out for the past twenty years, beginning with a survey of the 1000 hectare training forest of the University of Teheran, with three surveys so far. In 1995/96 an initial survey was carried out in the 1.8 million hectares of northern Iran’s forests with a total of 3611 permanent samples. In the Monday discussion critique was voiced that, in recent years in Switzerland, practically only large-area inventories have been further developed, but not inventories of individual enterprises. These should not be neglected, not least because of the advantages of longer time horizons in the data. It is not necessarily additional information that is required for enterprises but better instruments and models with which to interpret existing data.