bluuebunny/crossref_metadata_2025 huggingface dataset:
Psychosocial factors at work and risk of depression: a systematic review of the epidemiological evidence
Authors: Bonde J P E
Published: April 2008

Objectives:

Major depression is a leading cause of psychiatric morbidity and may be influenced by psychosocial factors in the workplace, although evidence so far remains circumstantial. This paper reviews follow-up studies addressing the risk of major depression and depressive symptoms relative to psychosocial stressors in the working environment and evaluates the evidence for causality.

Method:

Follow-up studies were identified by a systematic Medline search combining search terms for the outcome and measures of job-related psychosocial factors. The quality of the studies was evaluated using 22 criteria related to their potential for bias and confounding.

Results:

Sixteen company or population-based studies including some 63 000 employees were identified. Validated multi-item scales were used to measure perceived psychosocial stressors in most of the studies. Major depression was defined by clinical criteria in seven studies and by symptom scales in another seven. The follow-up period ranged from 1 to 13 years. The prevalence of depressive disorder varied substantially, suggesting a high degree of study heterogeneity. The adjusted relative risk for onset of a major depressive episode according to job stressors ranged from 0.5 to 1.5 in 44 of 61 reported associations with various psychosocial factor dimensions. Associations were strongest and most consistent for job strain defined as high demand and low decision latitude among men. Most studies shared common limitations such as lack of independent measures of exposure and outcome and potential confounding. Although a meta-analysis would technically be possible, heterogeneity across studies evidenced by variation in the prevalence of depression made this unfeasible.

Conclusion:

This review provides consistent findings that perception of adverse psychosocial factors in the workplace is related to an elevated risk of subsequent depressive symptoms or major depressive episode; however, methodological limitations preclude causal inference. Studies implementing objective measures of job stressors or independent outcome ascertainment are warranted.
An introduction to the Dorset special issue: transforming understanding of factors that regulate aquatic ecosystems on the southern Canadian Shield
Authors: Yan Norman D , Paterson Andrew M , Somers Keith M , Scheider Wolfgang A
Published: April 2008

This special issue demonstrates that aquatic ecosystems on the south-central Canadian Shield have changed in many ways over the last three decades. El Niño cycles have synchronized multilake dynamics in lake-water chemistry and in several components of the aquatic biota. Overlain on this cyclic regional pattern, phosphorus, sulphate, and calcium levels have all declined, whereas alkalinity has not yet risen in the most acid-sensitive study lakes, despite large reductions in SO2 emissions. Further, novel and unanticipated stressors have appeared, including nonindigenous predator introductions, Ca decline, salinity increase, and autumn spikes in metals following El Niño induced droughts. The resident biota are clearly responding not only to the familiar historical phosphorus and acid stressors, but also to the interactive effects of changes in multiple stressors in a warming environment. Lakes are best managed with an understanding of dominant limnological trends, their causes, and their responses to past management interventions. The research conducted at the Dorset Environmental Science Centre indicates “progress but no cigar” on acid rain, proof of climate variability as a direct and indirect regulator of south-central Shield ecosystems, and the emergence of novel stressors, the effects of which we cannot yet fully predict.
Grazers and Nutrients Simultaneously Limit Lotic Primary Productivity
Authors: Hill Walter R. , Boston Harry L. , Steinman Alan D.
Published: April 2008

Nitrate and phosphate were added to two of four flow through channels in a second-order stream in eastern Tennessee to raise nutrient concentrations to 3–4 times background, while two of four sets of colonized ceramic tiles in each channel were raised above the substratum to exclude grazing snails (Elimia clavaeformis). Snail grazing maintained a thin layer of periphyton dominated by Stigeoclonium basal cells, regardless of nutrient regime. Although nutrient effects on periphyton ash-free dry mass were statistically insignificant, nutrient additions significantly increased chlorophyll a, especially where snails were excluded. Snail densities were 89% higher in nutrient-enriched channels. Photosynthesis–irradiance data suggested that nutrient enrichment increased self-shading in the periphyton. Areal-specific productivity was simultaneously limited by grazing and low nutrient concentrations: snail exclusion and nutrient enrichment both increased productivity > 2 times. The negative effect of snails on areal-specific productivity was due to (1) reduction in biomass by cropping and (2) depression of chlorophyll-specific productivity. The means by which Elimia depresses chlorophyll-specific productivity is unclear, but the depression is clearly disadvantageous to food-limited grazers. Because Elimia was the dominant invertebrate, our results indicate that low nutrient concentrations limit secondary as well as primary production in autumn.
Molecular evolution of satellite DNA repeats and speciation of lizards of the genus Darevskia (Sauria: Lacertidae)
Authors: Grechko Vernata V. , Ciobanu Doina G. , Darevsky Ilya S. , Kosushkin Sergey A. , Kramerov Dmitri A.
Published: April 2008

Satellite DNA repeats were studied in Caucasian populations of 18 rock lizard species of the genus Darevskia. Four subfamilies (Caucasian Lacerta satellites (CLsat)I–IV) were identified, which shared 70%–75% sequence similarity. The distribution of CLsat subfamilies among the species was studied. All the species could be divided into at least 3 clades, depending on the content of CLsat subfamilies in each genome: “saxicola”, “rudis”, and “mixta” lizards. CLsatI was found in all studied species, but in very different quantities; the “saxicola” group contained this subfamily predominantly. The “rudis” group also contained CLsatIII, and the “mixta” group carried considerable amounts of CLsatII. The highest concentrations of CLsatI and CLsatII were detected in 2 ground lizards — D. derjugini and D. praticola, respectively. D. parvula predominantly carried CLsatIII. CLsatIV was found only in the Crimean species D. lindholmi. The distribution patterns of satellite subfamilies show possible postglacial speciation within the genus Darevskia. A hybrid origin of species that possess 2 or 3 CLsat subfamilies and important clarifications to the systematics of the genus are proposed.
Kinetic study and characterization of sewage sludge for its incineration
Authors: Rodriguez R. , Gauthier D. , Udaquiola S. , Mazza G. , Martinez O. , Flamant G.
Published: April 2008

The sewage sludge from San Juan, Argentina, was characterized in an attempt to improve the thermal treatment efficiency and to reduce the environmental impact of incineration. The ash content is about 50% dry basis, and its weight loss at 105 °C was high. Taking into account the moisture content, it required drying for an autothermal combustion, thus imposing an additional combustible for incineration. The sludge contains high concentrations of several trace elements, and all but Hg are two to fivefold more concentrated in its ash. Thermogravimetric analyses were carried out on dry samples of sludge in inert and oxidative atmosphere. Three peaks can be observed in all differential thermogravimetric curves during the organic matter decomposition. The pyrolysis curve is over the combustion curve and parallel to it up to high temperatures. A kinetic model of the sludge weight loss during its incineration, based on these studies and combining the multi-step pyrolysis and combustion processes, is proposed and discussed.
Mineral content of leaves of some common tropical forest trees and their associated soils in Ibadan, Nigeria
Authors: Sharma B. M.
Published: April 2008

Foliar and litter mineral content of six common and economically useful trees of tropical West Africa along with the associated soils were determined. Individual cations varied considerably, and seasonal changes in leaf as well as soil magnesium, sodium, and potassium content were not marked. Foliar nitrogen was maximum in the species studied compared with other foliar cations. Foliar calcium, potassium, and nitrogen were greater than that of magnesium, sodium, and phosphorus, respectively. Litter of Chlorophoraregia A. chev. and Afzeliaafricana Sm. is comparatively richer in nutrients, especially nitrogen. A significant positive linear correlation coefficient has been observed between leaf and litter magnesium as well as between soil and leaf, and for calcium, magnesium, and phosphorus between litter and soil for certain trees. However, the correlation is negative for magnesium between litter and soil in the case of Triplochitonscleroxylon K. Schum.
A tree survival model with application to species of the Great Lakes region
Authors: Buchman R. G. , Pederson S. P. , Walters N. R.
Published: April 2008

The survival model presented relates survival to tree size and vigor. Biological principles establish the general model form. The mathematical descriptor presented follows these biological principles with sufficient flexibility to portray the particular survival behavior of each species. Coefficients are presented for five major Great Lakes species. Although there were thousands of trees available for determining the coefficients for each species, each data set was deficient in large, slow-growing trees. Each set was augmented to guide the model in this range of size and growth. Applying the model to five species demonstrates the flexibility of its mathematical form. The model's performance is well established for the range of conditions underlying the test data.
Nondestructive estimation of foliar biomass in balsam fir
Authors: Piene Harald
Published: April 2008

A procedure for nondestructive estimation of foliar biomass in balsam fir (Abiesbalsamea (L.) Mill.) is described. The estimation is based on interrelationships between average shoot length, average needle length of the middle one-third of the shoot, and needle density. Strong positive correlations existed between needle length and needle weight, and between the reciprocal of needle length and needle density.
An alternative approach to conventional soil–site regression modeling
Authors: Verbyla David L. , Fisher Richard F.
Published: April 2008

The conventional approach in site-quality studies has been to develop a multiple regression site index model with soil–site measurements from randomly selected plots. This approach has several weaknessess: (i) a potential prediction bias associated with most stepwise regression procedures; (ii) low precision of soil–site regression models developed in areas with diverse topography and geologic formations; and (iii) poor representation of rare prime sites by random sampling. An alternative approach, aimed at minimizing these problems, is presented. Prediction bias potential (due to overfitting a model with too many predictor variables) can be reduced by using cross validation during model development. Models that accurately predict prime sites can be more useful than imprecise soil–site regression models. This can be accomplished by stratified random sampling from prime and nonprime site areas. Classification-tree analysis was used to develop a model that predicts prime ponderosa pine (Pinusponderosa Laws.) sites on the basis of vegetation and soil variables. Forest habitat type, percent sand content, and soil pH were model predictor variables. Cross-validation was used to estimate the accuracy of the classification tree as 88%. A multiple regression model developed from randomly selected plots consistently underestimated site index when it was applied to plots randomly selected from prime site areas. The conventional regression model was also misleading because it contained a predictor variable that was not significantly different between prime and nonprime sites.
Dehardening and budburst of Douglas-fir seedlings raised in three Pacific Northwest nurseries
Authors: Schuch Ursula K. , Duryea Mary L. , Fuchigami L. H.
Published: April 2008

This study was undertaken to test whether nursery location affected dehardening and budburst of Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco) seedlings from two seed sources. The seedlings, raised at three nurseries in Oregon and Washington, were measured with a whole-plant freezing test in January, February, and March, 1986. In general, seedlings raised at the nursery at highest elevation, and in a few cases, trees from the most northerly nursery, were more frost resistant than trees from a coastal nursery. From January to March, seedlings from the highest (975 m) seed source had less-hardy stem tissue than seedlings from the coastal source (450 m). A growth-chamber experiment confirmed the outdoor dehardening studies. A constant temperature of +5 °C with a 16-h photoperiod maintained cold hardiness, whereas +10 and +15 °C with a 16-h photoperiod promoted rapid dehardening after 20 days. The nursery environment influenced budburst; trees raised in the coastal nursery burst bud significantly earlier than trees from the other two nurseries. Trees of different provenances from the same nursery burst terminal buds only 2 days apart.
Height growth rates of young white spruce and lodgepole pine
Authors: Thomson Alan J. , McMinn Robert G.
Published: April 2008

Growth of different stock types of white spruce and lodgepole pine were compared on untreated sites and sites treated by scalping, where the surface soil and vegetation had been removed by bulldozing; mixing, where the vegetation had been incorporated into the underlying soil; and clipping, where the vegetation was clipped. Height increments varied with measurement period but had a pronounced peak around age 9. The slope of the linear regression of height versus age up to 10 years gave estimates of average annual growth rates which were used to compare stock type and treatment effects. The growth rate of a tree of a particular size at the time of the first measurement after outplanting could not be predicted with confidence. However, the pattern of growth rates in a stock type of a species subjected to a particular site treatment exhibited characteristics that could be used to differentiate species, stock, and site-treatment effects. In white spruce, there was a tendency for growth rate to be related to size at first measurement, though with high variability around the trend. In lodgepole pine, growth rate was independent of tree size at first measurement, and showed less variability.
Effects of stock type and site preparation on growth to crown closure of white spruce and lodgepole pine
Authors: Thomson Alan J. , McMinn Robert G.
Published: April 2008

Growth of white spruce (Piceaglauca (Moench) Voss) and lodgepole pine (Pinuscontorta Dougl.) seedlings was studied on six installations, each containing different stock types and site-preparation treatments. Stock types included styroplugs from different cavity sizes, bare-root stock, and transplant stock; site preparations included no treatment, scalping, inverting, and mixing. Fertilizer was also used in combination with some of these treatments on some installations. Site-preparation treatments that gave some degree of vegetation control generally led to higher growth rates, but there was considerable variability among and within installations. The slope of the linear relationship of height versus age up to 10 years gave an estimate of early growth which was suitable for comparing treatments, whereas average height increment in a later measurement period gave a better estimate of growth for projection purposes. A normal distribution of growth rates around a mean for a particular stock type and site-preparation method was used in conjunction with height–dbh and crown width–dbh relationships to project growth of trees to crown closure, assuming different densities. The age at crown closure depended on both growth rate and density, and average size at crown closure depended primarily on density.
STUECKELBERG: A FORERUNNER OF MODERN PHYSICS II
Authors: CIANFRANI FRANCESCO , LECIAN ORCHIDEA MARIA
Published: April 2008

We will investigate some aspects of Stueckelberg's work, which have contributed to the development of modern physics. On the one hand, the definition of diffuse boundaries in the calculation of scattering amplitudes will be reviewed, and compared with the other proposals by physicists of that time. On the other hand, the applications of Stueckelberg's description of a massive vector field in the Standard Model will be discussed.
ON THE THEORY AND PHENOMENOLOGY OF SPACETIME SYMMETRIES AT THE PLANCK SCALE
Authors: AMELINO-CAMELIA GIOVANNI , GUBITOSI GIULIA , MERCATI FLAVIO
Published: April 2008

We consider some alternative scenarios for the fate of Poincaré/Lorentz symmetry at the Planck scale, and we discuss some opportunities to test these scenarios.
ON THE LINEARIZATION OF THE BELINSKI-ALEKSEEV EXACT SOLUTION FOR TWO CHARGED MASSES IN EQUILIBRIUM
Authors: BINI D. , GERALICO A. , RUFFINI R.
Published: April 2008

A perturbative solution describing a two-body system consisting of a Reissner-Nordström black hole and a charged massive particle at rest is presented. The coincidence between such a solution and the linearized form of the recently obtained Belinski-Alekseev exact solution is explicitly shown.
THE BOUNDARY EFFECT ON ELECTRON-POSITRON PAIR-PRODUCTIONS
Authors: RUFFINI REMO , XUE SHE-SHENG
Published: April 2008

We present a study on the boundary effect on the rate of pair-production in Sauter electric field.
PARAMETRIZING FLUIDS IN CANONICAL QUANTUM GRAVITY
Authors: ZONETTI SIMONE , MONTANI GIOVANNI
Published: April 2008

The problem of time is an unsolved issue of canonical General Relativity. A possible solution is the Brown-Kuchař mechanism which couples matter to the gravitational field and recovers a physical, i.e. non vanishing, observable Hamiltonian functional by manipulating the set of constraints. Two cases are analyzed. A generalized scalar fluid model provides an evolutionary picture, but only in a singular case. The Schutz' model provides an interesting singularity free result: the entropy per baryon enters the definition of the physical Hamiltonian. Moreover in the co-moving frame one is able to identify the time variable τ with the logarithm of entropy.
ON THE ROLE OF VISCOSITY IN EARLY COSMOLOGY
Authors: CARLEVARO NAKIA , MONTANI GIOVANNI
Published: April 2008

We present a discussion of the effects induced by bulk viscosity on the very early Universe stability. The viscosity coefficient is assumed to be related to the energy density ρ via a power-law of the form ζ = ζ0ρs (where ζ0, s = const.) and the behavior of the density contrast in analyzed. In particular, we study both Einstein and hydrodynamic equations up to first and second order in time in the so-called quasi-isotropic collapsing picture near the cosmological singularity. As a result, we get a power-law solution existing only in correspondence to a restricted domain of ζ0. The particular case of pure isotropic FRW dynamics is then analyzed and we show how the asymptotic approach to the initial singularity admits an unstable collapsing picture.
EFFECTS OF STRUCTURAL AND CENTRAL METAL IONS MODIFICATION ON THE ELECTRONIC TRANSPORT PROPERTIES OF PORPHYRIN MOLECULAR JUNCTIONS
Authors: LONG MENG-QIU , WANG LINGLING , CHEN KE-QIU
Published: April 2008

We investigate the electronic transport properties of molecular devices constructed by porphyrin modulated with central metal ions by applying the elastic scattering Greens function theory approach in combination with the hybrid density functional theory. The effect of the porphyrin center metal ions and the twisting of the middle benzene rings on the electronic transport properties of the molecular devices is considered in detail. The results show that the the center metal ions can enhance the coupling of the molecule and electrode, while the twisting of the middle benzene rings is of a opposite effect.
OPTICAL AND STRUCTURAL PROPERTIES OF NANO-SIZED BARIUM STRONTIUM TITANATE (Ba0.6Sr0.4TiO3) THIN FILM
Authors: SINGH S. BOBBY , SHARMA H. B. , SARMA H. N. K. , PHANJOUBAM SUMITRA
Published: April 2008

Barium strontium titanate ( Ba0.6Sr0.4TiO3) or BST thin films on quartz substrates have been prepared by using a modified sol-gel processing technique. The starting materials are barium 2-ethylhexanoate Ba[CH3( CH2)3CH(C2H5) CO2]2, strontium 2-ethylhexanoate Sr[CH3( CH2)3CH(C2H5) CO2]2and titanium (IV) isopropoxide Ti[CH3CH3CHO ]4. The precursors Ti[CH3CH3CHO ]4except were synthesized in the laboratory. Transparent and crack-free films were fabricated on quartz substrates by spin coating. The as-fired films were found to be amorphous, which crystallized to cubic phase after annealing at 550°C in air for 1 hr. In this paper, we report the structural and optical properties of BST thin films prepared by the modified sol-gel process.
A purine-selective nucleobase/nucleoside transporter in PK15NTD cells
Authors: Hoque Kazi Mirajul , Chen Linxi , Leung George P. H. , Tse Chung-Ming
Published: April 2008

Nucleoside and nucleobase transporters are important for salvage of purines and pyrimidines and for transport of their analog drugs into cells. However, the pathways for nucleobase translocation in mammalian cells are not well characterized. We identified an Na-independent purine-selective nucleobase/nucleoside transport system in the nucleoside transporter-deficient PK15NTD cells. This transport system has 1,000-fold higher affinity for nucleobases than nucleosides with Kmvalues of 2.5 ± 0.7 μM for [3H]adenine, 6.4 ± 0.5 μM for [3H]guanine, 1.1 ± 0.1 mM for [3H]guanosine, and 4.2 ± 0.5 mM [3H]adenosine. The uptake of [3H]guanine (0.05 μM) was inhibited by other nucleobases and nucleobase analog drugs (at 0.5–1 mM in the order of potency): 6-mercaptopurine = thioguanine = guanine > adenine >>> thymine = fluorouracil = uracil. Cytosine and methylcytosine had no effect. Nucleoside analog drugs with modification at 2′ and/or 5 positions (all at 1 mM) were more potent than adenosine in competing the uptake of [3H]guanine: 2-chloro-2′-deoxyadenosine > 2-chloroadenosine > 2′3′-dideoxyadenosine = 2′-deoxyadenosine > 5-deoxyadenosine > adenosine. 2-Chloro-2′-deoxyadenosine and 2-chloroadenosine inhibited [3H]guanine uptake with IC50values of 68 ± 5 and 99 ± 10 μM, respectively. The nucleobase/nucleoside transporter was resistant to nitrobenzylthioinosine {6-[(4-nitrobenzyl) thiol]-9-β-d-ribofuranosylpurine}, dipyridamole, and dilazep, but was inhibited by papaverine, the organic cation transporter inhibitor decynium-22 (IC50of ∼1 μM), and by acidic pH (pH = 5.5). In conclusion, we have identified a mammalian purine-selective nucleobase/nucleoside transporter with high affinity for purine nucleobases. This transporter is potentially important for transporting naturally occurring purines and purine analog drugs into cells.
Reappraisal of H2S/sulfide concentration in vertebrate blood and its potential significance in ischemic preconditioning and vascular signaling
Authors: Whitfield Nathan L. , Kreimier Edward L. , Verdial Francys C. , Skovgaard Nini , Olson Kenneth R.
Published: April 2008

Hydrogen sulfide (H2S) is rapidly emerging as a biologically significant signaling molecule. Studies published before 2000 report low or undetectable H2S (usually as total sulfide) levels in blood or plasma, whereas recent work has reported sulfide concentrations between 10 and 300 μM, suggesting it acts as a circulating signal. In the first series of experiments, we used a recently developed polarographic sensor to measure the baseline level of endogenous H2S gas and turnover of exogenous H2S gas in real time in blood from numerous animals, including lamprey, trout, mouse, rat, pig, and cow. We found that, contrary to recent reports, H2S gas was essentially undetectable (<100 nM total sulfide) in all animals. Furthermore, exogenous sulfide was rapidly removed from blood, plasma, or 5% bovine serum albumin in vitro and from intact trout in vivo. To determine if blood H2S could transiently increase, we measured oxygen-dependent H2S production by trout hearts in vitro and in vivo. H2S has been shown to mediate ischemic preconditioning (IPC) in mammals. IPC is present in trout and, unlike mammals, the trout myocardium obtains its oxygen from relatively hypoxic systemic venous blood. In vitro, myocardial H2S production was inversely related to Po2, whereas we failed to detect H2S in ventral aortic blood from either normoxic or hypoxic fish in vivo. These results provide an autocrine or paracrine mechanism for myocardial coupling of hypoxia to H2S in IPC, i.e., oxygen sensing, but they fail to provide any evidence that H2S signaling is mediated by the circulation.
Loss of prokineticin receptor 2 signaling predisposes mice to torpor
Authors: Jethwa Preeti H. , I'Anson Helen , Warner Amy , Prosser Hayden M. , Hastings Michael H. , Maywood Elizabeth S. , Ebling Francis J. P.
Published: April 2008

The genes encoding prokineticin 2 polypeptide (Prok2) and its cognate receptor ( Prokr2/ Gpcr73l1) are widely expressed in both the suprachiasmatic nucleus and its hypothalamic targets, and this signaling pathway has been implicated in the circadian regulation of behavior and physiology. We have previously observed that the targeted null mutation of Prokr2 disrupts circadian coordination of cycles of locomotor activity and thermoregulation. We have now observed spontaneous but sporadic bouts of torpor in the majority of these transgenic mice lacking Prokr2 signaling. During these torpor bouts, which lasted for up to 8 h, body temperature and locomotor activity decreased markedly. Oxygen consumption and carbon dioxide production also decreased, and there was a decrease in respiratory quotient. These spontaneous torpor bouts generally began toward the end of the dark phase or in the early light phase when the mice were maintained on a 12:12-h light-dark cycle and persisted when mice were exposed to continuous darkness. Periods of food deprivation (16–24 h) induced a substantial decrease in body temperature in all mice, but the duration and depth of hypothermia was significantly greater in mice lacking Prokr2 signaling compared with heterozygous and wild-type littermates. Likewise, when tested in metabolic cages, food deprivation produced greater decreases in oxygen consumption and carbon dioxide production in the transgenic mice than controls. We conclude that Prokr2 signaling plays a role in hypothalamic regulation of energy balance, and loss of this pathway results in physiological and behavioral responses normally only detected when mice are in negative energy balance.
Resistance training induces qualitative changes in muscle morphology, muscle architecture, and muscle function in elderly postoperative patients
Authors: Suetta Charlotte , Andersen Jesper L. , Dalgas Ulrik , Berget Jakob , Koskinen Satu , Aagaard Per , Magnusson S. Peter , Kjaer Michael
Published: April 2008

Although the negative effects of bed rest on muscle strength and muscle mass are well established, it still remains a challenge to identify effective methods to restore physical capacity of elderly patients recovering from hospitalization. The present study compared different training regimes with respect to muscle strength, muscle fiber size, muscle architecture, and stair walking power in elderly postoperative patients. Thirty-six patients (60–86 yr) scheduled for unilateral hip replacement surgery due to hip osteoarthritis were randomized to either 1) resistance training (RT: 3/wk × 12 wk), 2) electrical stimulation (ES: 1 h/day × 12 wk), or 3) standard rehabilitation (SR: 1 h/day × 12 wk). All measurements were performed at baseline, at 5 wk and 12 wk postsurgery. After 12 wk of resistance training, maximal dynamic muscle strength increased by 30% at 60°/s ( P < 0.05) and by 29% at 180°/s ( P < 0.05); muscle fiber area increased for type I (+17%, P < 0.05), type IIa (+37%, P < 0.05), and type IIx muscle fibers (+51%, P < 0.05); and muscle fiber pennation angle increased by 22% and muscle thickness increased by 15% ( P < 0.05). Furthermore, stair walking power increased by 35% ( P < 0.05) and was related to the increase in type II fiber area ( r = 0.729, P < 0.05). In contrast, there was no increase in any measurement outcomes with electrical stimulation and standard rehabilitation. The present study is the first to demonstrate the effectiveness of resistance training to induce beneficial qualitative changes in muscle fiber morphology and muscle architecture in elderly postoperative patients. In contrast, rehabilitation regimes based on functional exercises and neuromuscular electrical stimulation had no effect. The present data emphasize the importance of resistance training in future rehabilitation programs for elderly individuals.
A Few Southern Spiders
Authors: Bryant Elizabeth B.
Published: April 2008

During recent years, several small collections of spiders
from Florida have been received at the Museum of Comparative
Zoology and among them are a few new and little
known species. All types are in the museum collection.
An Eocene Bittacus (Mecoptera)
Authors: Carpenter F. M.
Published: April 2008

In 1928 I described, as Palaeobittacus eocenicus, a
species of the family Bittacidae from Eocene strata in
Colorado. This has been the only representative of the
Mecoptera in Eocene deposits and the earliest unquestionable
record of a living family of the order. A second
Eocene bittacid has now turned up, this time among an
extensive collection of insects which Dr. Carl Parsons
and I made nearly twenty years ago in Utah. I appears
to be a true Bittacus with characteristic wing venation
and body features
Communication by Tandem Running in the Ant Genus Cardiocondyla
Authors: Wilson Edward O.
Published: April 2008

During field work in Puerto Rico in June,196o, the author had
the opportunity to study a hitherto little known form of communication
among worker ants. This behavior, which for convenience might
be called tandem running, involves the movement outward from the
nest of closely coupled tandem pairs, and it apparently functions as
a substitute or trail‐laying to recruit fellow workers to food sources.
On Puerto Rico, tandem running was studied more fully in the species
Cardiocondyla venustula Wheeler but was also observed in a second
member of the genus, C. emeryi Forel.
The Female of Bertrana Hieroglyphica Petrunkevitch (Araneae, Argiopidae)
Authors: Chickering Arthur M.
Published: April 2008

Four species of this very interesting genus are known at the present
time. Keyserling (1884) established the genus and described the first
known species from a group of females from Peras, Brazil. Two
other species have been described from South America by Simon
(1893); one of these was from Peru and the other from Para, Brazil.
Dr. Petrunkevitch was the first to describe a male which was the only
specimen in the genus collected at the Wilcox camp on the San Lorenzo
River. I now have about five dozen specimens from various
parts of Panama and the Canal Zone with both sexes well represented.
I have thought it worth while to publish a description of the female
with very brief attention paid to the male.
Australian Carabid Beetles XII. More Tachys
Authors: Darlington P. J.
Published: April 2008

This is, in effect, a continuation of Part X1 (Darlington 1962)
of my series of short papers on Australian Carabidae. The present
part deals with some additional groups of Tarhys.
Color Change and Life History Observations of the Spider Gea Heptagon (Araneae: Araneidae)
Authors: Sabath Laura Elsa
Published: April 2008

With the great interest in orb webs and their makers at the present
time (Witt, et al, 1968; Witt, ed., 1969) any observations on webs
and habits of orb weavers of genera other than the ones (Araneus,
Zygiella, Argiope and Uloborus) used currently by experimenters
are of interest.

Although spiders of the genus Gea are widespread, with species
in the subtropics and tropics around the world, no studies of life
history or careful web observations of any species of Gea have been
made. Since Gea is believed related to the much larger Argiope
(Levi, 1968), it was of interest to see whether Gea species have
similar habits, as resting in the center of the web and building a
stabilimentum (a zigzag swatch of silk above and below the hub),
and whether they made a similar eggcase. Levi (1968) reviews our
limited knowledge of Gea as follows: the web is vertical with a dense
viscid spiral and apparently without a stabilimentum; it is probably
made in low vegetation and the spider drops from it when slightly
disturbed.
Correlation Between Segment Length and Spine Counts in Two SpiderSpecies of Araneus (Araneae: Araneidae)
Authors: Carmichael L. David
Published: April 2008

Observations made on several hundred adult male spiders of
two species of Araneus indicate a highly significant correlation
(p<0.001) between the length of a segment (tibia of the second
leg) and the number of macrosetae (“spines”) present on the segment. This result is further supported by observations on the first
tibiae of about twenty male A. trifolfum, one of the two species, and
by a few observations on immatures of the two species. A short
summary of the methods used in taking the measurements and making
the calculations is followed by discussion of the implications of
this correlation with reference to species determination and geographic
variation
A Kleptoparasitic Cecidomyiid and Other Flies Associated With Spiders
Authors: Sivinski John , Stowe Mark
Published: April 2008

Spiders and their webs are predictable sources of insect cadavers.
A small number of animals regularly exploit this resource, either as
kleptoparasites or commensals, depending on whether symbionts
compete for the same prey (see Robinson and Robinson, 1977, for
more detailed terminology). Among the thieves are specialized
spiders (citations in Vollrath 1979a, 1979b), mature male and
juvenile spiders (Stowe 1978, citations in Nyffeler and Benz 1980),
Hemiptera (Davis and Russell 1969), a hummingbird (takes webbing
in addition to small insects, Young 1971), panorpid scorpion‐flies
(Thornhill 1975), Lepidoptera larvae (Robinson 1978), wasps
(Jeanne 1972), damselflies (Vollrath 1977), and a handful of flies
(reviews in Knab 1915; Bristowe 1931, 1941; Lindner 1937; Richards
1953; Robinson and Robinson 1977). Only a few of the reports on
Diptera kleptoparasites originate from North America (McCook
1889, Frost 1913, Downes and Smith 1969). With a single exception
(Downes and Smith 1969), all of the previously described kleptoparasitic
flies belong to the Brachycera and Cyclorrhapha. We
report here on a surprisingly diverse kleptoparasitic Diptera fauna
in north central Florida with a cecidomyiid (Nematocera) as its
dominant member.
Ecological Life History of Baetisca Berneri Tarter and Kirchner From a West Virginia Stream (Ephemeroptera: Baetiscidae)
Authors: Morris William R. , Chaffee Dwight L. , Tarter Donald C.
Published: April 2008

The primary objective of this investigation was to study the
ecological life history of the mayfly Baetisca berneri Tarter and
Kirchner in Laurel Fork, Mingo Co., West Virginia. Many authors,
including Say (1839), Traver (1931), Needham et al. (1935), Berner
( I940, 1955 ), Edmunds (I 960), Schneider and Berner (1963), Pescador
and Peters (1971, 1974), Lehmkuhl (1972), Tarter and Kirchner
(1978) and Chaffee and Tarter (1979), have reported studies on the
taxonomy and ecology of the genus Baetisca.
Notes on the Nests and Prey of Six Species of Pison in Australia (Hymenoptera: Sphecidae)
Authors: Evans Howard E. , Matthews Robert W. , Hook Allan
Published: April 2008

In the course of studies on the behavior of ground‐nesting
Sphecidae in Australia, we have occasionally made observations on
species that make free mud nests or that accept wooden trap nests (see
Krombein, 1967, for technique). Chief among these are species of the
genus Pison, which is abundantly represented in Australia. We report
here on six species, four of which have not previously been studied
(rufipes Shuckard, westwoodi Shuckard, marginatum Smith, and a
species near tibiale Smith). Data on two additional species (ignavum
Turner and spinolae Shuckard) confirm and enlarge upon previously
published reports. Our specimens have been compared with identified
material in the British Museum (Natural History), including the
types of Smith′s and Turner′s species. Voucher specimens have been
deposited in the Australian National Insect Collections, Canberra,
and at the University of Queensland, Brisbane. Some of these
observations were made by Evans and Matthews during the summer
of I969–70, others by Evans and Hook during the summer of
1979–80.
Predatory Behavior of the Basilica Spider, Mecynogea Lemniscata (Araneae, Araneidae)
Authors: Willey Marianne B. , Johnson Margaret A. , Adler Peter H.
Published: April 2008

Females of Mecynogea lemniscata (Walckenaer) are generalist
predators. Sixteen behavioral acts were described for M. lemniscata
preying on house flies, carpenter ants, and Asiatic oak weevils
in the field and laboratory. Behavioral sequences varied with
prey type, but generally began with plucking and diverged there‐after.
The predatory behavior of M. lemniscata is most similar to
that of the higher araneids.
Late Quaternary Ant Fossils From PackratMiddens (Hymenoptera: Formicidae): Implicationsfor Climatic Change in the Chihuahuan Desert
Authors: MacKay William P. , Elias Scott A.
Published: April 2008

Packrat (Neotoma spp.) middens in rock‐shelters provide important
paleoecological records for the desert regions of North America.
Specimens of various arthropod species accumulate in the
middens and are cemented into a black, tarry mass by packrat
urine.

We collected a variety of ants, including the genera Labidus,
Pseudomyrmex (?), Aphaenogaster, Crematogaster, Pheidole,
Pogonomyrmex, Solenopsis, Trachymyrmex, Liometopum, and
Camponotus in packrat middens from the Chihuahuan Desert. Our
data suggest a climatic change in the Chihuahuan Desert from
mesic to arid during the past 45,000 years. The coniferous forest,
oak‐juniper woodland of the early Holocene changed to desert‐grassland
about 8250 radiocarbon years before present (yr BP),
with a corresponding shift in ant species composition. By about
7500 yr BP, the presence of several arid adapted species suggests
the establishment of desert environments. Finally after about 2500
yr BP, we see the occurrence of primarily desert adapted ant
species in the Chihuahuan Desert, although mesic adapted species
continue to occur in moist "islands" within the area. The paleoenvironmental
data derived from the ant fossil records agrees closely
with previous reconstructions based on other arthropods.
Redescription of the Ant Leptothorax (S. STR.) Scamni Ruzsky, 1905
Authors: Heinze J. , Schulz A. , Radchenko A. G.
Published: April 2008

Worker and queen caste of the ant Leptothorax (sensu stricto)
scamni Ruzsky, 1905 are formally described and a neotype is designated.
The species is distinguished from other Leptothorax (s. str.) by extraordinarily long, finger‐shaped propodeal spines.
L. scamni appears to be a rather rare, patchily distributed ant in
alpine coniferous forests in the Caucasus (Russia and Armenia)
and northern Turkey.
Nestmate Copulation in the Neotropical Eusocial Wasp Polistes Instabilis de Saussure (Hymenoptera: Vespidae)
Authors: O′Donnell Sean
Published: April 2008

Copulation between individually marked nestmates of the
Neotropical eusocial wasp Polistes instabilis is reported. Polistes
copulations are rarely observed in the field; this observation is the
first documented case of nestmate copulation in the genus. Hamilton
(1964) predicted high rates of nestmate copulation for tropical
Polistes populations which have asynchronous colony cycles relative
to temperate populations. Nestmate copulation may lead to relatively
high levels of inbreeding in tropical Polistes species.
A Taxonomic Revision of the Orb Weaver Genus Acacesia (Araneae:Araneidae)
Authors: Glueck Susan
Published: April 2008

There are five species of Acacesia which range collectively
from southern North America to Argentina. Two are previously
known members of the genus. A. cornigera Petrunkevitch and A.
hamata (Hentz). Three of these are new species: A. villalobosi and
A. yacuiensis, fom southern Brazil, and A. benigna from Bolivia
and Peru.
Discovery and Designation of Type Specimens of Chrysomelidae(Coleoptera) From Argentina Described by E. von Harold in 1875
Authors: Furth David G. , Askevold Ingolf S. , Duckett Catherine N.
Published: April 2008

Type specimens of 14 species of Chrysomelidae from Cordova,
Argentina. collected by W. M. Davis and described by E. von
Harold in 1875, were discovered in the collections of the Museum
of Comparative Zoology (Harvard University). A few specimens
from some other museums such as the Museum für Naturkunde der
Humboldt‐Universität (Berlin), The Natural History Museum (London),
Institut Royal des Sciences Naturelles de Belgique (Brussels),
Museo Nacional de Hungaria (Budapest) are also apparently from
the original series. Lectotypes and paralectotypes are designated for
all species.
First Records of the Guest Ant Formicoxenus Quebecensis FrancoeurFrom Western Canada (Hymenoptera, Formicidae)
Authors: Buschinger A. , Schumann R. D. , Heinze J.
Published: April 2008

Formicoxenus quebecensis, a rare guest ant associated with
Myrmica alaskensis as yet had been found only in southern
Québec. Here we report on five new localities in Alberta and
British Columbia. The particular features of F. quebecensis, queen
and male polymorphism, correspond in both areas.
Two New Species of Coeligetes Jacoby From Malaysia (Coleoptera,Chrysomelidae, Galerucinae)
Authors: Mohamedsaid Mohamed S.
Published: April 2008

Coeligetes borneensis, n.sp. and Coeligetes wilcoxi, n.sp. are
described from Malaysia. The presence of the genus in Malaysia is
a new vecordo A key to Malaysian species is provided.
Forager Polymorphism and Foraging Ecology in the Leaf‐Cutting Ant, Atta colombica
Authors: Wetterer James K.
Published: April 2008

I compare forager size and foraging selectivity of the leaf‐cutting ant Atta colombica and that of its close relative Atta cephalotes. In both species, larger foragers cut fragments of greater mass and area, and at vegetation sources of greater specific density (mass/area). However, the size‐range of A. colombica foragers (1.5–56.8 mg) was wider than the range typical for A. cephalotes (1.4–32.1 mg). In A. colombica, the maxima workers (24–60 mg) commonly participate in foraging, making up 13% of all foragers in this study and in a previous study. In contrast, A. cephalotes maxima workers (24–100 mg) rarely forage (less than 1% of all foragers in two previous studies), but instead serve primarily as soldiers defending the nest. Thus, A. colombica maxima
workers are smaller and do not appear to be so specialized as soldiers as are A. cephalotes maxima workers. The broader size‐range of workers participating in foraging appears to allow A. colombica to exploit a wider range of resources than A. cephalotes, including tougher, denser vegetation and fallen fruits.
A Fossil Gymnopternus Loew (Diptera: Dolichopodidae) from the Florissant Beds, Colorado
Authors: Bickel Daniel J.
Published: April 2008

Gymnopternus lacustris n. sp. (Diptera: Dolichopodidae) is described from a compression fossil from the Eocene/Oligocene Florissant beds of Colorado, U.S.A. Gymnopternus has a rich recent fauna in North Americm and its fossil presence in these deposits is evidence of the essentially “modern” generic composition of the Tertiary dolichopodid fauna.
Thermomechanical Stresses in Fullerenes at Nanotube
Authors: Pugno Nicola M.
Published: April 2008

The thermomechanical stresses acting between a nanotube and fullerenes encapsulated on
it are computed. After a general formulation, based on elasticity, we have applied the analysis to C82@(10,10) or C60@(10,10) peapods finding stresses in the gigapascal range or vanishing, respectively. The analysis suggests that a thermal control could be used to produce smart
fullerenes at nanotube systems, for example, as two‐stage nanovectors for drug delivery.
Slowly Oscillating Continuity
Authors: Çakalli H.
Published: April 2008

A function f is continuous if and only if, for each point x0 in the domain, lim⁡n→∞f(xn) = f(x0), whenever lim⁡n→∞xn = x0. This is equivalent to the statement that (f(xn)) is a convergent sequence whenever (xn) is convergent. The concept of slowly oscillating continuity is defined in the sense that a function f is slowly oscillating continuous if it transforms slowly oscillating sequences to slowly oscillating sequences, that is, (f(xn)) is slowly oscillating whenever (xn) is slowly oscillating. A sequence (xn) of points in R is slowly oscillating if , where [λn] denotes the integer part of λn. Using ɛ > 0′s and δ′s, this is equivalent to the case when, for any given ɛ > 0, there exist δ = δ(ɛ) > 0 and N = N(ɛ) such that |xm − xn| < ɛ if n ≥ N(ɛ) and n ≤ m ≤ (1 + δ)n. A new type compactness is also defined and some new results related to compactness are obtained.
Characterization of Microstrip Ring with a Narrow Gap by an Iterative Method
Authors: Yeddes M. , Gharsallah A. , Gharbi A. , Baudrand H.
Published: April 2008

This paper presents an implementation of an iterative method based on the wave's concept, for analysing a ring resonator. This method includes a two-dimensional fourier modal transformation (2D-FMT) in a wave guide environment. The method has the advantage of simplicity in that it does not involve basis functions and inversion of matrices, as used in other calculation methods. Therefore, it is capable of analyzing larger bodies than other classical techniques. An implementation of the iterative calculation is shown for the extraction of S parameters of microwave components. The good agreement between simulation results and experimental published data justifies the design procedure and validates the present analysis approach.
Exact and Numerical Solutions of Poisson Equationfor Electrostatic Potential Problems
Authors: Yıldırım Selçuk
Published: April 2008

Homotopy perturbation method (HPM) and boundary element method (BEM) for calculating the exact and numerical solutions of Poisson equation with appropriate boundary and initial conditions are presented. Exact solutions of electrostatic potential problems defined by Poisson equation are found using HPM given boundary and initial conditions. The same problems are also solved using the BEM. The cell integration approach is used for solving Poisson equation by BEM. The problem region containing the charge density is subdivided into triangular elements. In addition, this paper presents a numerical comparison with the HPM and BEM.
Homotopy Perturbation Method for Solving Reaction‐Diffusion Equations
Authors: Wang Yu-Xi , Si Hua-You , Mo Lu-Feng
Published: April 2008

The homotopy perturbation method is applied to solve reaction‐diffusion equations. In this method, the trial function (initial solution) is chosen with some unknown parameters, which are identified using the method of weighted residuals. Some examples are given. The obtained results are compared with the exact solutions, revealing that this method is very efficient and the obtained solutions are of high accuracy.