bluuebunny/crossref_metadata_2025 huggingface dataset:
A Tangled Web of Terms: The Overlap and Unique Contribution of Involvement, Engagement, and Integration to Understanding College Student Success
Authors: Wolf-Wendel Lisa , Ward Kelly , Kinzie Jillian
Published: July 2009

Established theories and constructs long associated with student success, including involvement, engagement, and integration, provide common language and a body of knowledge to inform understanding of the challenges currently facing higher education. This paper examines how the theories and terms have evolved, explores how the terms are currently used, and considers their legacy for understanding contemporary concerns about student development and success.
Family Involvement: Impacts on Post-secondary Educational Success for First-Generation Appalachian College Students
Authors: Bryan Elizabeth , Simmons Leigh Ann
Published: July 2009

First-generation college students face a number of barriers to academic success and completion of their degrees. Using Bronfenbrenner’s (1989) ecological theory as a framework, qualitative research was used to examine the experiences of 10 first-generation Appalachian Kentucky university students (mean age = 21 years) and factors they attributed to their educational success. Content analysis was used to analyze the data. Seven themes representing participants’ experiences in a university setting were identified: (a) close-knit families and communities, (b) separate identities, (c) knowledge of college procedures, (d) pressure to succeed, (e) returning home, (f ) the pervasiveness of poverty, and (g) the importance of early intervention programming. Additional areas for research and potential policy adjustments for universities serving this population are presented.
Reducing Sexual Violence on Campus: The Role of Student Leaders as Empowered Bystanders
Authors: Banyard Victoria L. , Moynihan Mary M. , Crossman Maria T.
Published: July 2009

Sexual violence is a widespread problem for college communities. Students, faculty, and staff are increasingly involved in prevention efforts. To date, however, evaluation of sexual violence prevention programs has shown mixed results. One promising new practice teaches segments of college communities to be engaged, positive bystanders. It aims to both raise awareness about the problem of sexual violence and build skills that individuals can use to end it. The framework is grounded in research about the causes of sexual assault on campuses and factors identified by health behavior theories for changing attitudes and behavior. Evaluation of data using a bystander model is just beginning to appear. The current study presents a brief evaluation of one bystander program conducted with two groups of student leaders on one midsize public university campus in the Northeast. Results show the program to be effective, even among a group of student leaders who have a higher level of general awareness of campus community problems and training in working with students. Implications for programming and future research are discussed.
Finishing High School: Alternative Pathways and Dropout Recovery
Authors: Tyler John H. , Lofstrom Magnus
Published: July 2009

John Tyler and Magnus Lofstrom take a close look at the problems posed when students do not complete high school. The authors begin by discussing the ongoing, sometimes heated, debate over how prevalent the dropout problem is. They note that one important reason for discrepancies in reported dropout rates is whether holders of the General Educational Development (GED) credential are counted as high school graduates. The authors also consider the availability of appropriate student data. The overall national dropout rate appears to be between 22 and 25 percent, but the rate is higher among black and Hispanic students, and it has not changed much in recent decades. Tyler and Lofstrom conclude that schools are apparently doing about as well now as they were forty years ago in terms of graduating students. But the increasingly competitive pressures associated with a global economy make education ever more important in determining personal and national well-being.

A student’s decision to drop out of school, say the authors, is affected by a number of complex factors and is often the culmination of a long process of disengagement from school. That decision, not surprisingly, carries great cost to both the student and society. Individual costs include lower earnings, higher likelihood of unemployment, and greater likelihood of health problems. Because minority and low-income students are significantly more likely than well-to-do white students to drop out of school, the individual costs fall unevenly across groups. Societal costs include loss of tax revenue, higher spending on public assistance, and higher crime rates.

Tyler and Lofstrom go on to survey research on programs designed to reduce the chances of students’ dropping out. Although the research base on this question is not strong, they say, close mentoring and monitoring of students appear to be critical components of successful programs. Other dropout-prevention approaches associated with success are family outreach and attention to students’ out-of-school problems, as well as curricular reforms. The authors close with a discussion of second-chance programs, including the largest such program, the GED credential.
Expanding Policy Options for Educating Teenagers
Authors: Stern David
Published: July 2009

David Stern argues that some basic features of the American high school must be modified if it is to serve all students successfully. He notes, for example, that only three-quarters of U.S. high school students graduate four years after beginning ninth grade and that the National Assessment of Educational Progress found no improvement in reading or mathematics for seventeen-year-olds between 1971 and 2004. The nation’s system for educating teenagers, says Stern, seems to be stuck, despite the constant efforts of teachers and repeated waves of reform.

Citing two widely accepted public purposes of educating teenagers—preparation for civic participation and for economic self-sufficiency—Stern proposes four new strategies to achieve those goals. He draws on empirical evidence suggesting that these are promising directions for research and policy, but acknowledges that existing studies provide only limited guidance.

First, he says, schools should continue the current trend toward integrating educational options to provide young people with skills and experiences that pave the way to both college and careers. Second, states and districts should tie education funding not simply to the number of students attending school, but also to what young people learn, whether they graduate, and whether they find jobs or enroll in postsecondary education. Such a move, he argues, would encourage teaching and learning formats that use students’ time more effectively. Third, more adults in addition to classroom teachers should be involved in educating teenagers. Other adults acting as academic advisers, learning coaches, student advocates, internship supervisors, mentors, and college counselors could help guide the education of teenagers inside and outside of school and provide some relief for the chronic shortage of teachers. Fourth, schools should expand the options for educating teenagers outside of geographically fixed schools. Combining improved Internet-based curriculum with internships and civic engagement projects, for example, may produce better results for many young people and also may promote academic achievement for teenagers who do not thrive in conventional classrooms and for those who face academic and social challenges when they move from one place to another. Stern argues that the limited success of today’s high schools makes such new initiatives well worth trying and evaluating.
Diplomatic Arts: Hickes against Mabillon in the Republic of Letters
Authors: Hiatt Alfred
Published: July 2009

In his 1705 Thesaurus the English antiquarian George Hickes published lengthy criticisms of the approach to forged
documents advocated by Jean Mabillon in his seminal De re diplomatica . Mabillon argued against rash rejection of
swathes of documents, and emphasized the mixture of genuine and false material in many archives; Hickes alleged
that Mabillon's position would allow even rank forgeries to be defended as genuine. The disagreement between
Hickes and Mabillon casts light on the particular intellectual and religious orientations of the two scholars, but more
broadly on the fault-lines across which debate took place within the Republic of Letters.
Kavalan Reduplication
Authors: Lee Amy Pei-jung
Published: July 2009

Kavalan is an endangered Formosan plains-tribe language still actively spoken in daily life by fewer than one hundred native speakers. This paper investigates reduplication in Kavalan in terms of pattern and meaning. Having reviewed the relevant literature (e.g., Li 1982, 1996; Lin 1996; Chang 2000; Li and Tsuchida 2006; Lee 2007), I propose that Kavalan reduplication can be generalized into the following patterns: (1) disyllabic reduplication; (2) monosyllabic reduplication; (3) Ca-reduplication; and (4) lexicalized reduplication. Realization of reduplicants in Kavalan is phonologically driven. A flowchart is used to indicate the process of reduplicant formation. The discussion on the meanings is based on a morphosemantic perspective (cf. Kiyomi 1993), dividing reduplication into verbal and nominal types. The former manifests the meanings of iteration, continuation, intensity, intensification (with sia- or saa- ), attenuation, reciprocity (with sim- ), and pretense (with sa- ); the latter has meanings of plurality, distributiveness, indefiniteness, and smell (with su- ). Ca-reduplication is used to indicate intensification (e.g., the increasing quality of color terms), and lexicalized reduplication is often found with onomatopoetic verbal roots and names of fauna, especially birds and insects, and flora.
“Away! Away to Falun!”: J. G. Gahn and the Application of Enlightenment Chemistry to Smelting
Authors: Fors Hjalmar
Published: July 2009

The paper discusses what happened when Enlightenment chemical reformers came face to face with the complex world of artisanal production. It investigateS what eighteenth-century chemists did in practice to gain access to—and authority over—the crafts. It argues that chemistry had to be construed as a useful applied science through a complex process of social negotiation. The case examined here shows how Johan Gottlieb Gahn, a student of Uppsala professor Torbern Bergman and a close collaborator of the chemist-apothecary Carl Wilhelm Scheele, tried to improve artisanal smelting practices in the Swedish mining town of Falun. The paper argues that his success—if it can be called such—depended more on skillfull negotiations with mine owners, artisanal smelters, academic chemists, and mining officials than on access to a superior (or even adequate) chemical theory. The first part of the paper considers the importance of patronage and demonstrates the nature of the contacts between university chemists and mining officials employed by the Swedish state. The second part of the paper discusses Gahn’s attempts to reform the smelting process at the great copper mine of Falun, drawing on his interactions with smelters, mine-owners, and his superiors to explore the related issues of knowledge, control, and social standing.
A Thing for Stories
Authors: Herzig Rebecca
Published: July 2009

Taking historian William Cronon’s 1992 essay, “A Place for Stories,” as its point of departure, this essay considers the character, purposes, and uses of narratives about “things” generated by self-identified historians of technology. Following Cronon, Herzig proposes closer scrutiny of narrative within SHOT, as part of a broader discussion of the changing roles and responsibilities of professional historians.
Irradiation-Induced Grain-Boundary Solute Segregation and Its Effect on Ductile-to-Brittle Transition Temperature in Reactor Pressure Vessel Steels
Authors: Nishiyama Yutaka , Yamaguchi Masatake , Onizawa Kunio , Iwase Akihiko , Matsuzawa Hiroshi
Published: July 2009

A study on grain-boundary segregation and embrittlement in terms of the Charpy ductile-to-brittle transition temperature (DBTT) has been performed for the neutron-irradiated A533B steels with typical contents of impurities of Japanese reactor pressure vessel ones. The neutron irradiation was conducted at 563 K to a fluence of 1.3× 1024n/m2 (E>1 MeV) using material testing reactors. The neutron irradiation induced the P and Ni segregation and the reduction in C in some cases at grain-boundaries. The increase in the P segregation at high fluence (>5×10 23n/m2, E>1 MeV) was less than 0.1 in monolayer coverage for the steels with the bulk content of P not exceeding 0.02 wt%. The hardening more strongly affected the DBTT shift than the P segregation for those steels. The reduction in segregated C that enhances the grain-boundary cohesion by neutron fluence is not large enough to cause the DBTT shift.
Metabolic syndrome and its components are associated with increased thyroid volume and nodule prevalence in a mild-to-moderate iodine-deficient area
Authors: Ayturk Semra , Gursoy Alptekin , Kut Altug , Anil Cuneyd , Nar Asli , Tutuncu Neslihan Bascil
Published: July 2009

Objective

Metabolic syndrome (MetS) is a cluster of metabolic abnormalities with insulin resistance (IR) as a major component. It has been recently questioned whether MetS and its related components are associated with functional and morphological alterations of the thyroid gland. The aim of our study is to examine thyroid volume and nodule prevalence in a case–control study of patients with MetS in a mild-to-moderate iodine-deficient area.

Design

Two hundred and seventy-eight patients with MetS were randomly matched for age, gender, and smoking habits with 261 subjects without MetS. Serum TSH, free tri-iodothyronine and thyroxine, and the level of IR, which was estimated by the homeostasis model assessment for IR, as well as other MetS parameters were evaluated. Thyroid ultrasonography was performed in all subjects. All subjects with thyroid nodules >1 cm were offered to undergo thyroid fine needle aspiration biopsy.

Results

TSH was significantly positively correlated with the presence of MetS diagnosis. There was no association between free thyroid hormone levels and MetS and its related components. Mean thyroid volume was significantly higher in patients with MetS than in controls (17.5±5.5 vs 12.2±4.2 ml, P<0.0001). Also the percentage of patients with thyroid nodules was significantly higher in patients with MetS (50.4 vs 14.6%, P<0.0001). Subjects were also divided into two groups according to the presence of IR. The group of subjects with IR had increased thyroid volume and nodule formation. The odds ratio for the development of thyroid nodule in the presence of IR was 3.2. TSH as well as all MetS components were found to be independent predictors for thyroid volume increase. IR but not TSH was found to be correlated with thyroid nodule formation. Thyroid cancer was diagnosed in 3 out of 38 patients with MetS who agreed to have a biopsy (7.9%). None of the subjects in the control group was diagnosed to have thyroid cancer.

Conclusions

The results suggest that patients with MetS have significantly increased thyroid volume and nodule prevalence. Multivariate regression analysis model demonstrated that the presence of IR contributed substantially to this increased risk. Our data provide the first evidence that IR is an independent risk factor for nodule formation in an iodine-deficient environment.
Oocyte quality in lactating dairy cows fed on high levels of n-3 and n-6 fatty acids
Authors: Fouladi-Nashta Ali A , Wonnacott Karen E , Gutierrez Carlos G , Gong Jin G , Sinclair Kevin D , Garnsworthy Philip C , Webb Robert
Published: July 2009

Different fatty acid (FA) sources are known to influence reproductive hormones in cattle, yet there is little information on how dietary FAs affect oocyte quality. Effects of three dietary sources of FAs (supplying predominantly palmitic and oleic, linoleic (n-6) or linolenic (n-3) acids) on developmental potential of oocytes were studied in lactating dairy cows. A total of 12 Holstein cows received three diets containing rumen inert fat (RIF), soyabean or linseed as the main FA source for three periods of 25 days in a Latin-square design. Within each period, oocytes were collected in four ovum pick-up sessions at 3–4 day intervals. FA profiles in plasma and milk reflected profiles of dietary FA sources, but major FAs in granulosa cells were not affected. Dietary FA source did not affect plasma concentrations of leptin, insulin, IGF1, GH, or amino acids. RIF led to a higher proportion of cleaved embryos than soya or linseed, but blastocyst yield and embryo quality were not affected. It is concluded that the ovary buffers oocytes against the effects of fluctuations in plasma n-3 and n-6 FAs, resulting in only modest effects on their developmental potential.
AKT (protein kinase B) is implicated in meiotic maturation of porcine oocytes
Authors: Kalous Jaroslav , Kubelka Michal , Šolc Petr , Šušor Andrej , Motlík Jan
Published: July 2009

The aim of this study was to investigate the involvement of the serine/threonine protein kinase AKT (also called protein kinase B) in the control of meiosis of porcine denuded oocytes (DOs) maturedin vitro. Western blot analysis revealed that the two principal AKT phosphorylation sites, Ser473 and Thr308, are phosphorylated at different stages of meiosis. In freshly isolated germinal vesicle (GV)-stage DOs, Ser473 was already phosphorylated. After the onset of oocyte maturation, the intensity of the Ser473 phosphorylation increased, however, which declined sharply when DOs underwent GV breakdown (GVBD) and remained at low levels in metaphase I- and II-stage (MI- and MII-stage). In contrast, phosphorylation of Thr308 was increased by the time of GVBD and reached maximum at MI-stage. A peak of AKT activity was noticed around GVBD and activity of AKT declined at MI-stage. To assess the role of AKT during meiosis, porcine DOs were cultured in 50 μM SH-6, a specific inhibitor of AKT. In SH-6-treated DOs, GVBD was not inhibited; on the contrary, a significant acceleration of meiosis resumption was observed. The dynamics of the Ser473 phosphorylation was not affected; however, phosphorylation of Thr308 was reduced, AKT activity was diminished at the time of GVBD, and meiotic progression was arrested in early MI-stage. Moreover, the activity of the cyclin-dependent kinase 1 (CDK1) and MAP kinase declined when SH-6-treated DOs underwent GVBD, indicating that AKT activity is involved in the regulation of CDK1 and MAP kinase. These results suggest that activity of AKT is not essential for induction of GVBD in porcine oocytes but plays a substantial role during progression of meiosis to MI/MII-stage.
Vascular endothelial growth factor regulates germ cell survival during establishment of spermatogenesis in the bovine testis
Authors: Caires Kyle C , de Avila Jeanene , McLean Derek J
Published: July 2009

Vascular endothelial growth factor-A (VEGFA) is a hypoxia-inducible peptide essential for angiogenesis and targets nonvascular cells in a variety of tissues and cell types. The objective of the current study was to determine the function of VEGF during testis development in bulls. We used an explant tissue culture and treatment approach to test the hypothesis that VEGFA-164 could regulate the biological activity of bovine germ cells. We demonstrate that VEGFA, KDR, and FLT1 proteins are expressed in germ and somatic cells in the bovine testis. Treatment of bovine testis tissue with VEGFAin vitroresulted in significantly more germ cells following 5 days of culture when compared with controls. Quantitative real-time RT-PCR analysis determined that VEGF treatment stimulated an intracellular response that prevents germ cell death in bovine testis tissue explants, as indicated by increased expression ofBCL2relative toBAXand decreased expression ofBNIP3at 3, 6, and 24 h during culture. Blocking VEGF activityin vitrousing antisera against KDR and VEGF significantly reduced the number of germ cells in VEGF-treated testis tissue to control levels at 120 h. Testis grafting providedin vivoevidence that bovine testis tissue treated with VEGFA for 5 days in culture contained significantly more differentiating germ cells compared with controls. These findings support the conclusion that VEGF supports germ cell survival and sperm production in bulls.
The effects of growth factors on in vitro-cultured porcine testicular cells
Authors: Kuijk Ewart W , Colenbrander Ben , Roelen Bernard A J
Published: July 2009

Cell lines from neonate porcine testis were cultured and characterized and the effect of growth factors were investigated, in order to determine the requirements for the establishment of porcine male germ cell lines. In primary cultures, three different colony types with distinctive morphologies could be recognized. From colonies resembling mouse spermatogonial stem cells (SSCs), two cell lines were derived and maintained for nine passages after which proliferation stopped. Growth of these cell lines depended on the growth factors leukemia inhibitory factor (LIF), epidermal growth factor (EGF), glial derived neurotrophic factor (GDNF), and fibroblast growth factor (FGF). In both cell lines NANOG, promyelocytic leukemia zinc-finger (PLZF), and EPCAM, were expressed at higher levels and GFRA1, ITGA6, and THY1 at lower levels than in neonate porcine testis. Primary cultures of neonate pig testis were subjected to a factorial design of the growth factors LIF, GDNF, EGF, and FGF. EGF and FGF had a positive effect on the number and size of the SSC-like colonies. Addition of EGF and FGF to primary cell cultures of neonate pig testis affected the expression of NANOG, PLZF, POU5F1, and GATA4, whereas effects of LIF or GDNF could not be detected. FGF decreased the expression levels of NANOG, a marker for pluripotency also expressed in neonatal porcine male germ cells. FGF decreased expression of PLZF and enhanced the expression of pluripotency-related gene POU5F1 and Sertoli cell marker GATA4. EGF had a positive effect on PLZF expression levels and counteracted the positive effect of FGF on GATA4 expression. These results suggest that FGF can impede successful derivation of porcine SSCs from neonate pig testis.
Potential immunomodulatory role of VIP in the implantation sites of prediabetic nonobese diabetic mice
Authors: Roca Valeria , Calafat Mario , Larocca Luciana , Ramhorst Rosanna , Farina Mariana , Franchi Ana Maria , Pérez Leirós Claudia
Published: July 2009

Among several factors known to modulate embryo implantation and survival, uterine quiescence and neovascularization, maternal immunotolerance through the Th1/Th2 cytokine balance towards a Th2 profile, local regulatory T-cell (Treg) activation, and high levels of progesterone were assigned a prominent role. Vasoactive intestinal peptide (VIP) is a neuroimmunopeptide that has anti-inflammatory effects, promotes Th2 cytokines and CD4+CD25+FOXP3+Treg activation, and stimulates exocrine secretion, smooth muscle relaxation, and vasodilatation favoring uterus quiescence. The goal of the present work was to explore the participation of VIP in the implantation sites of normal and pregnant prediabetic nonobese diabetic (NOD) females, a mouse strain that spontaneously develops an autoimmune exocrinopathy similar to Sjögren's syndrome. Our results indicate a reduction in litter size from the third parturition onwards in the NOD female lifespan with increased resorption rates. Progesterone systemic levels were significantly decreased in pregnant NOD mice compared with BALB/c mice, although the allogeneic response to progesterone by spleen cells was not impaired. VIP receptors,Vipr1andVipr2(Vpac1andVpac2), were expressed at the implantation sites and VIP induced leukemia inhibitory factor (LIF) and Treg marker expression in both strains; however, a reducedVipexpression was found in NOD implantation sites. We conclude that the reduced birth rate at 16-week-old NOD mice with a Th1 systemic cytokine profile involves resorption processes with a lower expression of VIP at the sites of implantation, which acts as a local inducer of pro-implantatory LIF and Treg activation.
The position of the germinal vesicle and the chromatin organization together provide a marker of the developmental competence of mouse antral oocytes
Authors: Bellone Michele , Zuccotti Maurizio , Redi Carlo Alberto , Garagna Silvia
Published: July 2009

Based on their chromatin organization, antral oocytes can be classified into two classes, namely surrounded nucleolus (SN, chromatin forms a ring around the nucleolus), and not surrounded nucleolus (NSN, chromatin has a diffuse pattern). Oocytes of both classes are capable of meiotic resumption, but while SN oocytes, following fertilization, develop to term, NSN oocytes never develop beyond the two-cell stage. A recent study has shown that the position of the germinal vesicle (GV) can be used as a morphological marker predictive of oocyte meiotic competence, i.e. oocytes with a central GV have a higher meiotic competence than oocytes with an eccentric GV. In the present study, we have associated both markers with the aim of identifying, with more accuracy, the oocytes' developmental competence. Following their isolation, antral oocytes were classified on the basis of both SN and NSN chromatin configuration and their GV position, matured to metaphase II and fertilized in vitro. We demonstrated that the position of the GV is a good marker to predict the oocytes' developmental competence, but only when associated with the observation of the chromatin organization.
Anti-Nociceptive and Anti-Inflammatory Activities of Extracts from the Stem Bark of Croton macrostachyus (Euphorbiaceae) in Mice and Rats
Authors: Kamanyi Albert , Mbiantcha Marius , Nguelefack Telesphore Benoit , Ateufack Gilbert , Watcho Pierre , Ndontsa Blanche Laure , Tane Pierre
Published: July 2009

The present study evaluates the anti-nociceptive and anti-inflammatory properties of the aqueous and methylene chloride/methanol (CH2Cl2 / CH3OH) extracts of the stem bark of Croton macrostachyus. The extracts administered orally at the doses of 150, 300 and 600 mg/kg were examined against pain induced by acetic acid, formalin and pressure and against inflammation induced by carragenan, histamine and formalin. Both extracts induced a significant dose-dependent (P < 0.001) reduction in the number of abdominal constrictions induced by acetic acid. The three doses of the two extracts also significantly reduced (P < 0.001) the two phases of pain induced by formalin. At the dose of 600 mg/kg, the aqueous and the CH2Cl2 / CH3OH extracts exhibited a significant analgesic activity against pressure-induced pain. The two extracts also exhibited anti-inflammatory activity, the CH2Cl2 / CH3OH extract being the most active, inhibited acute inflammation induced by carrageenan, histamine and formalin. Both extracts also significantly reduced the chronic inflammation induced by formalin. These results show that the aqueous and CH2Cl2 / CH3OH extracts of the stem bark of Croton macrostachyus possess analgesic and anti-inflammatory properties. These findings are in accordance with the traditional use of the plant and indicate that Croton macrostachyus is a potent source of analgesic and anti-inflammatory principles.
Modeling of Adsorption of Chromium(VI) on Activated Carbons Derived from Corn (Zea mays) Cob
Authors: Oubagaranadin John U. Kennedy , Murthy ZVP
Published: July 2009

Chromium in its trivalent and hexavalent form in the environment is toxic above certain concentrations. Cr(VI), which is more toxic than Cr(III), was chosen in this work and removed from aqueous solutions of potassium dichromate by adsorption onto physically and chemically activated carbons derived from Zea mays(corn or maize) cob, an agricultural waste product. Adsorption studies were done at the optimum pH of 2 and at the room temperature of 30°C. The aim of the work was to study the adsorption equilibrium and kinetic data with various isotherm and kinetic models. The best fit to the equilibrium data was provided by the 3-parameter Fritz-Schluender model followed by the 2-parameter Langmuir model. The adsorption isotherms were favorable and the adsorption on chemically activated carbons improved as the impregnation ratio was increased. Kinetic modeling showed that the fractional power model provided the best fit followed by the second-order Ritchie's equation. The adsorption of Cr(VI) on the activated carbons was film-diffusion controlled.
Volatile constituents of Erodium cicutarium (L.) L’ Hérit. (Geraniaceae)
Authors: Radulović Niko , Dekić Milan , Stojanović-Radić Zorica , Palić Radosav
Published: July 2009

Essential oils from Erodium cicutarium were obtained by hydrodistillation (samples consisting of entire plants (ec1), leaves and stems (ec2)) and analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS), resulting in a total of 177 components being identified. The essential oils were of a very similar chemical composition and consisted mainly of aliphatic compounds and their derivatives. Fatty acids and fatty acid derived compounds were the most common, 51.3% (ec1) and 60.1% (ec2), followed by carotenoid derived compounds, 12.6% (ec1) and 20.2% (ec2), and then terpenoids, 14.9% (ec1) and 14.2% (ec2). The main constituents in the oils were hexadecanoic acid, 22.8% (ec2) and 35.9% (ec1) and hexahydrofarnesyl acetone, 10.8% (ec2) and 11.6% (ec1). The results obtained differ markedly from those previously reported for the same species.
Chemical composition and antimicrobial activity of Satureja hortensis L. essential oil
Authors: Mihajilov-Krstev Tatjana , Radnović Dragan , Kitić Dušanka , Zlatković Bojan , Ristić Mihailo , Branković Suzana
Published: July 2009

Essential oil of Satureja hortensis L. was analyzed by GC and GC/MS and tested by a broth micro-well dilution method for activity against multiresistant clinical isolates of pathogenic bacteria from 10 different genera: Klebsiella, Escherichia, Proteus, Staphylococcus, Streptococcus, Pseudomonas, Enterococcus, Enterobacter, Citrobacter and Acinetobacter. The main compounds in the oil were carvacrol (67%), γ-terpinene (15.3%) and p-cymene (6.73%). The oil showed activity against all tested strains. MIC/MBC values were in the range of 0.78-25 μl/ml, with the exception of the strain P. aeruginosa. Microbicidal concentration for this particular strain (50 μl/ml) was the highest tested concentration. The oil showed inhibitory and bactericidal effect at the same concentration (MIC=MBC) for all but three strains.
The combined effect of Cd2+ and ACh on action potentials of Nitellopsis obtusa cells
Authors: Kisnierienė Vilma , Sakalauskas Vidmantas , Pleskačiauskas Aleksandras , Yurin Vladimir , Rukšėnas Osvaldas
Published: July 2009

Interrelations between the action of acetylcholine (ACh) and cadmium ions (Cd2+) on bioelectrogenesis of Nitellopsis obtusa cells were investigated. We analyzed repetitively triggered action potentials (AP), their reproducibility, shape and dynamics of membrane potential after AP induction. ACh significantly increased membrane permeability only at high concentrations (1 mM and 5 mM). Repolarisation level of action potential after the first stimulus was much more positive in all cells treated with ACh as compared to the control. Differences of membrane potentials between points just before the first and the second stimuli were 23.4±.0 mV (control); 40.4±5.9 mV (1 mM ACh solution) and 57.7 ± 8.5 mV (5 mM ACh solution). Cd2+ at 20 μM concentration was examined as a possible inhibitor of acetylcholinesterase (AChE) in vivo. We found that cadmium strengthens depolarizing effect of acetylcholine after the first stimulus. The highest velocity of AP repolarization was reduced after ACh application and Cd2+strengthened this effect. There were no differences in dynamics of membrane potential after repetitively triggered action potentials in ACh or ACh and Cd2+ solutions. This shows that cadmium in small concentration acts as inhibitor of acetylcholinesterase.
Nicotine-induced memory impairment by increasing brain oxidative stress
Authors: Hritcu Lucian , Ciobica Alin , Gorgan Lucian
Published: July 2009

Male Wistar rats were subjected to chronic nicotine treatment (0.3 mg/kg; 7 continuous days) and their memory performance was studied by means of Y-maze and multi-trial passive avoidance tasks. Nicotine significantly decreased spontaneous alternation in Y-maze task and step-through-latency in the multi-trial passive avoidance task, suggesting effects on both short-term memory and long-term memory, respectively. In addition, nicotine induced neuronal apoptosis, DNA fragmentation, reduced antioxidant enzymes activity, and increased production of lipid peroxidation and reactive oxygen species, suggesting pro-oxidant activity. Our results provide further support that nicotine-induced memory impairment is due to an increase in brain oxidative stress in rats.
Biosorption of phosphate from synthetic wastewater by biosolids
Authors: Hrenovic Jasna , Rozic Mirela , Ivankovic Tomislav , Farkas Anamarija
Published: July 2009

The aim of this study was to determine the potential of phosphate (P) removal from wastewater by biosolids prepared by the immobilization of P-accumulating bacteria onto organic bentonite. Organic bentonite was prepared by treating bentonite clay with quaternary ammonium salt — cetyltrimetylammonium (CTA) bromide. Cation exchange capacity (CEC) of the bentonite was found to be 179.0 meq/100 g of the dry bentonite. The CTA occupied ca. 175% of the CEC. Modification of bentonite with CTA in amounts higher than 55% of the CEC resulted in the change of zeta potential of particles from negative to positive. Only in reactors containing organic bentonite samples occupied with 3.5 and 28% of the CEC was P efficiently removed from wastewater by combined adsorption and bacterial uptake in the biomass. Organic bentonite samples with higher CTA loadings (from 55 to 175% of the CEC) showed bactericidal effects. To enhance P removal from wastewater in the aerated biological system, biosolids consisting of P-accumulating bacteria and organic bentonite can be used, but special attention should be given to the configuration of sorbed CTA molecules and its potential desorption.
Lipopeptides as anti-infectives: a practical perspective
Authors: Pirri Giovanna , Giuliani Andrea , Nicoletto Silvia , Pizzuto Lorena , Rinaldi Andrea
Published: July 2009

Lipopeptide antibiotics represent an old class of antibiotics that were discovered over 50 years ago, which includes the old polymyxins but also new entries, such as the recently approved daptomycin. They generally consist of a hydrophilic cyclic peptide portion attached to a fatty acid chain which facilitates insertion into the lipid bilayer of bacterial membranes. This review presents an overview of this class of antibiotics, focusing on their therapeutic applications and putting particular emphasis on chemical modifications introduced to improve their activity.
Fungal septins: one ring to rule it all?
Authors: González-Novo Alberto , Vázquez de Aldana Carlos , Jiménez Javier
Published: July 2009

Septins are a conserved family of GTP-binding proteins found in living organisms ranging from yeasts to mammals. They are able to polymerize and form hetero-oligomers that assemble into higher-order structures whose detailed molecular architecture has recently been described in different organisms. In Saccharomyces cerevisiae, septins exert numerous functions throughout the cell cycle, serving as scaffolds for many different proteins or as diffusion barriers at the bud neck. In other fungi, septins are required for the proper completion of diverse functions such as polarized growth or pathogenesis. Recent results from several fungi have revealed important differences in septin organization and regulation as compared with S. cerevisiae, especially during Candida albicans hyphal growth and in Ashbya gossypii. Here we focus on these recent findings, their relevance in the biology of these eukaryotes and in consequence the “renaissance” of the study of septin structures in cells showing a different kind of morphological behaviour.
Sound production and chorusing behaviour in larvae of Icosium tomentosum
Authors: Kočárek Petr
Published: July 2009

Substrate-borne vibrations produced by the larvae of non-lamiinae longicorn Icosium tomentosum Lucas, 1854 (Cerambycidae: Cerambycinae) are also emitted as loud sounds audible to humans. The vibrations consists of a long sequence of regularly repeated pulses at a rate of 8 pulses per second. The duration of the pulses are 0.061±0.009 s and the interpulse intervals are 0.065±0.015 s. The mechanism of vibration generation is the scraping by strongly sclerotised mandibles against the bark. Chorusing behaviour previously unknown in Cerambycidae larvae have been observed when the larvae feeding in the same or nearby branches starting to produce the audible vibrations in reaction to the vibrations of another larva.
FACTORS INFLUENCING LIGHT SCATTERING IN THE EYE
Authors: Ikaunieks G. , Ozolinsh M. , Stepanovs A. , Lejiete V. , Reva N.
Published: July 2009

FACTORS INFLUENCING LIGHT SCATTERING IN THE EYE

Our vision in the twilight or dark is strongly affected by the intraocular light scattering (straylight). Of especial importance is to assess this phenomenon in view of the night driving. The authors have studied the spectral dependence of retinal stray-light and estimated the possibility to reduce it with yellow filters and small apertures. For the measurements the direct compensation flicker method was used. The results show that this spectral dependence is close to Rayleigh's scattering (∝λ-4). As could be expected from the known data, the yellow filter should reduce retinal straylight, especially for blue light. However, in the experiments this scattering was not removed with such a filter but instead slightly increased. The optical apertures reduced light scattering in the eye, especially for red color.
Dicle Ringing Station (Se Turkey) - Ringing Results and Seasonal Bird Migration Dynamics in 2003-2005
Authors: Filar Monika , Biricik Murat
Published: July 2009

Dicle Ringing Station (Se Turkey) - Ringing Results and Seasonal Bird Migration Dynamics in 2003-2005

Dicle Ringing Station is a field station in the campus of Dicle University, Diyarbakır (SE Turkey), and has been working since 2003. From that year it also belongs to the SEEN organization (SE European Bird Migration Network). The paper includes information collected during three autumn and one spring seasons. Totally, 5393 birds were ringed. Detailed information about study site and ringing results are reported in the paper.
Stopover of Robins (Erithacus rubecula) On Autumn Migration Through the Polish Baltic Coast
Authors: Meina Łukasz , Ginter Małgorzata , Rosińska Katarzyna
Published: July 2009

Stopover of Robins (Erithacus rubecula) On Autumn Migration Through the Polish Baltic Coast

Data were collected during autumn migration at three ringing stations of the Operation Baltic: Bukowo-Kopań, Mierzeja Wiślana and Hel. Apart from different localization at the Polish Baltic coast, these places differ also in topography and habitat. Only data from years with the highest number of caught birds were used in the analyses, thus altogether the data on more than 25 500 ringed Robins and 1700 retraps were included. Based on migration dynamics graphs and number of retraps, a stopover index was calculated. Next, the index values were compared between days with a high and low number of caught birds and also between different fat categories. Differences between birds caught once and retraps were shown in relation to daily activity, age structure and fat level. Additionally changes in weight and fat level between first and last control in retraps were considered. At Mierzeja Wiślana and Hel the stopover index decreased in the course of autumn season in contrast to Bukowo-Kopań where an increasing trend was observed. At Bukowo-Kopań more birds decided to stopover than at Mierzeja Wiślana and Hel but at Mierzeja Wiślana Robins stayed longer than at other stations. Moreover, at Mierzeja Wiślana a half of departing retraps increased in fat level while at the other stations only ca 20% of retraps. Our results showed that in Robins the weak body condition is a decisive factor to stopover after crossing the sea. Differentiation in food resources and competition between individuals had an effect on the stopover index. Stopover duration at different ringing stations can depend on distance which birds cover before landing at the coast.
Acute effects of static stretching on muscle strength
Authors: Torres Juliana , Conceição Mario , de Oliveira Sampaio Adriane , Dantas Estélio
Published: July 2009

Acute effects of static stretching on muscle strength

Study aim: To assess the effects of static passive maximal stretching on muscle performance in order to clarify the existing controversies.

Material and methods: Two randomly selected groups of the Brazilian Air Force personnel were studied: experimental (n = 15), subjected to 3 bouts of static passive stretching exercises of wrist flexors and extensors (beyond a mild discomfort). Every bout lasted 10 s and was followed by a 30-s rest. The control group (n = 15) performed no exercises. Muscle strength was measured with a handgrip dynamometer before and 20 min after the test.

Results: Subjects from the experimental group had the pre-exercise handgrip strength significantly higher than postexercise (by about 7%; p<0.01). No significant decrease was noted in the control group.

Conclusions: Static passive stretching induces decreases in muscle strength.
Mobile surgical services in primary care in a rural and remote setting: Experience and evidence from Yala, Cross River State, Nigeria
Authors: Monjok Emmanuel , Essien Ekere J.
Published: July 2009

Surgical conditions account for 11 to 15% of the global burden of disease. Yet, surgical services are very scarce in the rural areas of Nigeria where approximately 60 to 80% of the population resides. Among other basic contributing factors is the shortage of surgical workforce, since Nigeria’s few surgeons practise in the urban centre of the major cities. One way to respond to this acute shortage of surgeons is the training of generalist medical doctors to undertake surgery in rural areas. The introduction of mobile surgical services in rural populations as part of the existing primary health care activities in the Local Government Areas (districts) can reduce surgical morbidity and mortality in Nigeria. This can be done by the generalist physician with training and experience in surgery using local health staff and simple surgical equipment. A number of recommendations are made.
Low‐Threshold Distributed‐Feedback Lasers Based on Pyrene‐Cored Starburst Molecules with 1,3,6,8‐Attached Oligo(9,9‐Dialkylfluorene) Arms
Authors: Xia Ruidong , Lai Wen‐Yong , Levermore Peter A. , Huang Wei , Bradley Donal D. C.
Published: July 2009

Here, a detailed characterization of the optical gain properties of sky‐blue‐light‐emitting pyrene‐cored 9,9‐dialkylfluorene starbursts is reported; it is shown that these materials possess encouragingly low laser thresholds and relatively high thermal and environmental stability. The materials exhibit high solid‐state photoluminescence (PL) quantum efficiencies (>90%) and near‐single‐exponential PL decay transients with excited state lifetimes of ∼1.4 ns. The thin‐film slab waveguide amplified spontaneous emission (ASE)‐measured net gain reaches 75–78 cm−1. The ASE threshold energy is found to remain unaffected by heating at temperatures up to 130 °C, 40 to 50 °C above Tg. The ASE remained observable for annealing temperatures up to 170 or 200 °C. 1D distributed feedback lasers with 75% fill factor and 320 nm period show optical pumping thresholds down to 38–65 Wcm−2, laser slope efficiencies up to 3.9%, and wavelength tuning ranges of ∼40 nm around 471–512 nm. In addition, these lasers have relatively long operational lifetimes, with N1/2 ≥ 1.1 × 105 pulses for unencapsulated devices operated at ten times threshold in air.
Controlling Light Emission in Luminescent Solar Concentrators Through Use of Dye Molecules Aligned in a Planar Manner by Liquid Crystals
Authors: Verbunt Paul P. C. , Kaiser Anton , Hermans Ko , Bastiaansen Cees W. M. , Broer Dirk J. , Debije Michael G.
Published: July 2009

A luminescent solar concentrator (LSC) is a potential low‐cost enhancement of the standard large‐area silicon photovoltaic panels for the generation of electricity from sunlight. In this work, guest–host systems are investigated using anisotropic fluorescent dyes and liquid crystal mesogens to control the direction of emitted light in the LSC. It is determined that up to 30% more light is emitted from the edge of an LSC waveguide with planar dye alignment parallel to the alignment direction than from any edge of an LSC with no alignment (isotropic). The aligned samples continue to show dichroic performance after additions of both edge mirrors and rear scattering layer.
Diamond Transistor Array for Extracellular Recording From Electrogenic Cells
Authors: Dankerl Markus , Eick Stefan , Hofmann Boris , Hauf Moritz , Ingebrandt Sven , Offenhäusser Andreas , Stutzmann Martin , Garrido Jose A.
Published: July 2009

The transduction of electric signals from cells to electronic devices is mandatory for medical applications such as neuroprostheses and fundamental research on communication in neuronal networks. Here, the use of diamond with its advantages for biological applications as a new material for biohybrid devices for the detection of cell signals is investigated. Using the surface conductivity of hydrogen‐terminated single‐crystalline diamond substrates, arrays of solution‐gate field‐effect transistors were fabricated. The characterization of the transistors reveals a good stability in electrolyte solutions for at least 7 days. On these devices, cardiomyocyte‐like HL‐1 cells as well as human embryonic kidney cells (HEK293), which were stably transfected with potassium channels, are cultured. Both types of cells show healthy growth and good adhesion to the substrate. The diamond transistors are used to detect electrical signals from both types of cells by recording the extracellular potential. For the HL‐1 cells, the shape of action potentials can be resolved and the propagation of the signal across the cell layer is visible. Potassium currents of HEK293 cells are activated with the patch‐clamp technique in voltage‐clamp mode and simultaneously measured with the field‐effect transistors. The ion sensitivity of the diamond surface enables the detection of released potassium ions accumulated in the cleft between transistor and cell.
On the Synthesis of Carbon Nanofibers and Nanotubes by Microwave Irradiation: Parameters, Catalysts, and Substrates
Authors: Druzhinina Tamara , Hoeppener Stephanie , Schubert Ulrich S.
Published: July 2009

The microwave (MW)‐assisted synthesis of one dimensional carbon systems is introduced as a promising approach to improve the speed and cost‐effectiveness of the fabrication process. Improved reaction conditions are generated by direct MW heating and synthesis under advanced reaction conditions. The influence of the reaction conditions is investigated and the importance of individual process parameters on the synthesis is discussed. Temperature and pressure data recorded during the irradiation process are analyzed in detail and allow the determination of essential process parameters. This leads to improved reaction conditions, better control of the one‐dimensional carbon nanosystems by tuning the catalyst materials, and allows expanding this approach to initiate the synthesis on a variety of different substrates, such as quartz glass and mica.