bluuebunny/crossref_metadata_2025 huggingface dataset:
Food‐availability dependent premature metamorphosis in the bean blister beetle Epicauta gorhami (Coleoptera: Meloidae), a hypermetamorphic insect that feeds on grasshopper eggs in the larval stage
Authors: Terao Misato , Hirose Yuzuru , Shintani Yoshinori
Published: March 2014

Larvae of the bean blister beetle, Epicauta gorhami, feed on only grasshopper eggs and undergo hypermetamorphosis with pseudopupal diapause in the fifth instar. Whether E. gorhami larvae enter pseudopupal diapause or pupate directly from the fourth instar is controlled by temperature and photoperiod. In nature, larvae are confronted with a significant variation in the availability of food, suggesting the possibility that feeding conditions may also affect the diapause incidence. Here, we addressed this issue by changing the feeding conditions in the fourth instar under conditions of 16 h light : 8 h dark (LD 16 : 8) at 25°C. Food deprivation reduced the length of instar and increased the tendency to pupate, leading to the early eclosion of a small adult. Even non‐feeding fourth‐instar larvae pupated. Regardless of the timing of food deprivation, the post‐feeding larval period was constant and equivalent to that of ad libitum‐fed larvae, suggesting that premature exhaustion of the food supply triggers the initiation of pupation. In agreement with these results, when larvae were fed on intact grasshopper egg pods of various sizes from four species, those that fed on smaller egg pods had a decreased tendency to pseudopupate (i.e., to enter diapause). Food‐deprived larvae showed a clearer photoperiodic response and had a shorter critical day‐length. Thus, in E. gorhami, feeding conditions do not affect pupation success, but do affect the tendency to pupate or pseudopupate. This is the first report of the occurrence of premature pupation in carnivorous insects. We discuss our findings in the context of the natural history and behavioral ecology of E. gorhami.
Insights on the association of American Cetoniinae beetles with ants
Authors: Puker Anderson , Rosa Cassiano S. , Orozco Jesús , Solar Ricardo R. C. , Feitosa Rodrigo M.
Published: March 2014

Cetoniinae beetles (Coleoptera: Scarabaeoidea: Scarabaeidae) can occupy the nests of social insects. In many cases the beetles located within the colonies of social insects encounter a place of shelter and food resources for both adults and immatures. Despite the numerous cohabitation records, the relationship of Cetoniinae beetles with their ant hosts remains mostly unexplored. In this review we provide hypotheses explaining this ant–beetle association. A conceptual model is presented on the processes underpinning the occupation of the nest and the consequences that unfold after occupation, including: (i) death of the ant colony; (ii) death of beetles; and (iii) coexistence. We also provide an exhaustive list of American Cetoniinae beetle species found associated with ants and discuss the symbiotic relationships occurring between the beetles and their host ants.
The discovery of epidermal tight junctions
Authors: Ozawa Toshiyuki , Sugawara Koji , Tsuruta Daisuke
Published: March 2014

It was previously thought that the skin barrier is composed singly by the stratum corneum. However, this concept was overturned by the report of Tsukita's group in 2002. They convinced us that tight junctions exist in the stratum granulosum of the epidermis, with the constituent proteins being occludin, claudin‐1 and claudin‐4. However, more than 30 years before this, Hashimoto et al. described the possible existence of tight junctions in the epidermis in ‘Intercellular spaces of the human epidermis as demonstrated with lanthanum’ in 1971. Dr. Hashimoto observed lanthanum nitrate‐injected human skin by electron microscopy. He discovered that the injected lanthanum penetrated the intercellular spaces of the basal and spinous layers of the epidermis and then moved towards the skin surface until penetration was halted in the granular cell layer near the stratum corneum. He described the cell‐to‐cell adhesion structures that blocked the movement of lanthanum as ‘truly tight junctions’. Thus, this was the first description of the existence of tight junctions in the epidermis. However, the presence of these structures was denied by others and was forgotten. Thanks to the discovery of claudin, the existence of tight junctions between epidermal keratinocytes was finally confirmed. It is interesting that Hashimoto's finding was eventually proved to be correct three decades later as a result of progress in molecular biology. This article encourages us to recognize the importance of careful observation in the molecular biology era.
Patient participation in hospital care: Nursing staffs' point of view
Authors: Kolovos Petros , Kaitelidou Daphne , Lemonidou Chrysoula , Sachlas Athanasios , Zyga Sofia , Sourtzi Panayota
Published: March 2014

The aim was to investigate nursing staff's perceptions related to patient participation and the parameters affecting it during nursing care. A cross‐sectional study with both a quantitative and qualitative orientation was conducted. The sample consisted of all nursing staff working in medical and surgical wards in three Greek hospitals. A questionnaire was developed and the data were analysed with exploratory factor analysis, whereas content analysis was used for qualitative data. Nursing staff perceived participation as the process of information giving to patients, communication of symptoms by patients and compliance with the staff's orders. ‘Information providing’ and ‘ability to influence and responsibility’ were significant aspects of the content of participation, whereas the parameters affecting participation were related to patients, nursing staff and the care context. These results support patient engagement in dialogue and shared decision‐making, while highlighting the need to implement participation systematically and stimulate changes in nursing care organization.
Prevalence of metabolic syndrome and cardiovascular risk level in a vulnerable population
Authors: Kim Chun‐Ja , Park JeeWon , Kang Se‐Won
Published: March 2014

This study examined the prevalence of metabolic syndrome and the risk level of cardiovascular disease (CVD) in a vulnerable population of 407 subjects in Korea. This descriptive study was a part of the Tailed Health Visiting Service Program, using baseline data from public health centres in Suwon, Korea. The definition of metabolic syndrome was based on the National Cholesterol Education Program criteria, and risk of CVD was estimated according to the Framingham study equation. This study demonstrated that the prevalence of metabolic syndrome was 40.8% higher and the risk of CVD was significantly 3.1 times higher among those with metabolic syndrome than among those without it. Of those with metabolic syndrome, 50.6% overall and 81.1% of men had a high risk for CVD. These findings suggest a need to screen and prevent the risk of CVD in vulnerable populations with metabolic syndrome.
The relationship between South Korean clinical nurses' attitudes toward organizations and voluntary turnover intention: A path analysis
Authors: Kim Jong Kyung , Chang Sun Ju
Published: March 2014

The purpose of this study was to examine the relationship between attitudes toward their organizations and voluntary turnover intention among South Korean clinical nurses. Data from a total of 312 clinical nurses in six hospitals in South Korea were collected for the study. Both hierarchical multiple regression analysis and path analysis were used to analyse the data. The overall fit of the hypothetical model was good. Voluntary turnover intention was found to have significant direct pathways to job embeddedness and organizational commitment. Organizational commitment and satisfaction with organizational rewards had indirect pathways to voluntary turnover intention through job embeddedness. All variances explained 62.3% of the voluntary turnover intention scores. The findings suggest that greater job embeddedness, organizational commitment and satisfaction with organizational rewards lead to lower voluntary turnover intention among clinical nurses in South Korea.
The perceptions of nurses towards barriers to the safe administration of medicines in mental health settings
Authors: Hemingway Steve , McCann Terence , Baxter Hazel , Smith George , Burgess‐Dawson Rebecca , Dewhirst Kate
Published: March 2014

The purpose of this study was to investigate perceptions of barriers to safe administration of medicines in mental health settings. A cross‐sectional survey was used, and 70 mental health nurses and 41 students were recruited from a mental health trust and a university in Yorkshire, UK. Respondents completed a questionnaire comprising closed‐ and open‐response questions. One item, which contained seven sub‐items, addressed barriers to safe administration of medication. Seven themes—five nurse‐ and prescriber‐focused and two service user‐focused—were abstracted from the data, depicting a range of barriers to safe administration of medicines. Nurse‐ and prescriber‐focused themes included environmental distractions, insufficient pharmacological knowledge, poorly written and incomplete medication documentation, inability to calculate medication dosage correctly, and work‐related pressure. Service user‐focused themes comprised poor adherence to medication regimens, and cultural and linguistic communication barriers with service users. Tackling medication administration error is predominantly an organizational rather than individual practitioner responsibility.
Internationally recruited neonatal nurses' experiences in the National Health Service in London
Authors: Alexis Obrey , Shillingford Adeline
Published: March 2014

The aim of this study was to explore internationally recruited neonatal nurses' (IRNNs) perceptions of their experiences of working in the National Health Service (NHS) in London. This was an exploratory study. A purposive sample of 13 nurses (all females) from two teaching hospitals in London participated in this study. Semi‐structured face‐to‐face interviews were used to capture IRNNs views of working in the NHS in London. Five themes emerged, namely: motivation to migrate, lack of preparation for neonatal nurses, environmental conditions impacting on care delivery, neonatal nurses deskilling, and role restrictions as well as professional development. The findings of this study provide first‐hand insights from the subjective perspectives of IRNN experiences. IRNNs experienced some challenges to their working lives; however, good preparation is important when recruiting them to work in the NHS.
Academic challenges and positive aspects: perceptions of male nursing students
Authors: Abushaikha L. , Mahadeen A. , AbdelKader R. , Nabolsi M.
Published: March 2014

Background

Nursing shortage remains a global issue that emphasizes the need for both male and female nurses. Understanding the educational experiences of male nursing students may help in recruiting and retaining male nurses in the nursing profession.

Aim

The aim of this study was to explore the challenges and positive aspects that undergraduate male nursing students encounter during the course of their study.

Methods

A qualitative research design using inductive content analysis approach was used to explore perceptions of 20 undergraduate male nursing students in a baccalaureate nursing programme at a major public university in Jordan.

Results

Content analysis revealed two major themes: challenges (academic difficulties, biased policies, no social life, negative views of nursing and negative self‐view) and positive aspects (personal benefits of studying nursing, every home need a nurse and nursing is a science).

Discussion

The findings added new insights and knowledge regarding the educational experiences of undergraduate male nursing students in a developing country, which is an understudied population. Understanding the challenges and positive aspects of nursing education from the perspectives of undergraduate male nursing students may help nursing educators better understand their students' educational experiences and help clarify their roles and responsibilities in dealing with these issues.

Conclusion

Nursing as a career should continue to be a viable choice for both male and female students to address global nursing shortages. This can be ensured by decreasing challenges and supporting positive aspects that nursing students face during their nursing education.

Implications for Nursing and Health Policy

Higher education policy makers can use the findings of this study to appreciate the challenges that university students face. They can also reconsider existing policies that may hinder the acceptance of male student into nursing programmes and contribute to educational challenges.
Kinetics of Cristobalite Formation in Sintered Silica
Authors: Breneman Ryan C. , Halloran John W.
Published: March 2014

The kinetics of the cristobalite transformation are reported for sintered silica glass from 1200°C to 1650°C and plotted as a time–temperature–transformation diagram. The 1200°C–1350°C transformation data were fit to the Johnson–Mehl–Avrami–Kolmogorov expression with an time exponent of 3.0 ± 0.6 and an apparent activation energy of 555 ± 24 kJ/mol for the kinetic constant. The temperature of maximum transformation rate was found to fall between 1500°C and 1600°C. Seeding amorphous silica powder with cristobalite resulted in accelerated transformation kinetics. Silica glass powder containing residual quartz had faster transformation kinetics than fully amorphous powder seeded with cristobalite.
The Cobalt Zinc Spinel Ferrite Nanofiber: Lightweight and Efficient Microwave Absorber
Authors: Huang Xiaogu , Zhang Jing , Xiao Shaorong , Chen Guosheng
Published: March 2014

To solve the heavy mass problem of the traditional spinel ferrite using as the microwave absorber, the CoxZn(1−x)Fe2O4 (x = 0.2, 0.4, 0.6, 0.8) ferrite nanofibres were synthesized by electrospinning method. The phase composition, morphology, and electromagnetic properties were analyzed. The results showed that all the as‐prepared CoxZn(1−x)Fe2O4 ferrites exhibited the homogeneous nanofibrous shape. The saturation magnetization and coercivity were enhanced by tuning the Co2+ content. The electromagnetic loss analysis indicated that the Co0.6Zn0.4Fe2O4 ferrite nanofiber performed the strongest microwave attenuation ability. The microwave absorbing coating containing 15 wt% of Co0.6Zn0.4Fe2O4 ferrite nanofiber showed the reflection loss less than −10 dB in the whole X‐band and 80% of the Ku‐band frequencies. Meanwhile, the surface density was only 2.4 Kg/m2.
Low‐Temperature Preparation of β‐Si3N4 Porous Ceramics with a Small Amount of Li2O–Y2O3
Authors: Fan Lei , Zhou Meng , Wang Hongjie , Shi Zhongqi , Lu Xuefeng , Wang Chao
Published: March 2014

Porous β‐Si3N4 ceramics are sintered at 1600°C in N2 and postheat treated at 1500°C under vacuum using Li2O and Y2O3 as the sintering additives. The partial sintering and phase transformation are promoted at low temperature by the addition of Li2O. The addition of Y2O3 is advantageous for the formation of high aspect ratio β‐Si3N4 grains. After postheat treatment, a large amount of intergranular glassy phase is removed, and the Li content in the samples is decreased. By this method, the β‐Si3N4 porous ceramic with a porosity of 54.1% and high flexural strength of 110 ± 8.1 MPa can be prepared with a small amount of sintering additives, 0.66 wt% Li2O and 0.33 wt% Y2O3, and it is suitable for high‐temperature applications.
Preparation of Transparent 3Y‐TZP Nanoceramics with No Low‐Temperature Degradation
Authors: Xiong Yan , Fu Zhengyi , Pouchly Vaclav , Maca Karel , Shen Zhijian
Published: March 2014

The progresses of the relative density, average grain size (GS), and maximum pore size entering into the final sintering stage are investigated in 3 mol% yttria‐stabilized tetragonal zirconia polycrystals (3Y‐TZP) compacts in the range of 87%~99% theoretical density. It is found that during conventional pressureless sintering, the pores in the compact enlarged dramatically, which appears to be the major obstacle for preparing fully dense nanoceramics. Transparent 3Y‐TZP nanoceramics with an average GS of 87 nm were prepared by exploiting microstructural refinement on nanoscale. The yields a maximal optical transmittance of 67% and shows no noticeable low‐temperature degradation after 100 h aging at 134°C under a hydrothermal pressure of two bars.
Formation of Community‐Based Hypertension Practice Networks: Success, Obstacles, and Lessons Learned
Authors: Dart Richard A. , Egan Brent M.
Published: March 2014

Community‐based practice networks for research and improving the quality of care are growing in size and number but have variable success rates. In this paper, the authors review recent efforts to initiate a community‐based hypertension network modeled after the successful Outpatient Quality Improvement Network (O'QUIN) project, located at the Medical University of South Carolina. Key lessons learned and new directions to be explored are highlighted.
Relative immaturity and ADHD: findings from nationwide registers, parent‐ and self‐reports
Authors: Halldner Linda , Tillander Annika , Lundholm Cecilia , Boman Marcus , Långström Niklas , Larsson Henrik , Lichtenstein Paul
Published: March 2014

Background

We addressed if immaturity relative to peers reflected in birth month increases the likelihood of ADHD diagnosis and treatment.

Methods

We linked nationwide Patient and Prescribed Drug Registers and used prospective cohort and nested case–control designs to study 6–69 year‐old individuals in Sweden from July 2005 to December 2009 (Cohort 1). Cohort 1 included 56,263 individuals diagnosed with ADHD or ever used prescribed ADHD‐specific medication. Complementary population‐representative cohorts provided DSM‐IV ADHD symptom ratings; parent‐reported for 10,760 9‐year‐old twins born 1995–2000 from the CATSS study (Cohort 2) and self‐reported for 6,970 adult twins age 20–47 years born 1959–1970 from the STAGE study (Cohort 3). We calculated odds ratios (OR:s) for ADHD across age for individuals born in November/December compared to January/February (Cohort 1). ADHD symptoms in Cohorts 2 and 3 were studied as a function of calendar birth month.

Results

ADHD diagnoses and medication treatment were both significantly more common in individuals born in November/December versus January/February; peaking at ages 6 (OR: 1.8; 95% CI: 1.5–2.2) and 7 years (OR: 1.6; 95% CI: 1.3–1.8) in the Patient and Prescribed Drug Registers, respectively. We found no corresponding differences in parent‐ or self‐reported ADHD symptoms by calendar birth month.

Conclusion

Relative immaturity compared to class mates might contribute to ADHD diagnosis and pharmacotherapy despite absence of parallel findings in reported ADHD symptom loads by relative immaturity. Increased clinical awareness of this phenomenon may be warranted to decrease risk for imprecise diagnostics and treatment. We speculate that flexibility regarding age at school start according to individual maturity could reduce developmentally inappropriate demands on children and improve the precision of ADHD diagnostic practice and pharmacological treatment.
Effect of music on pain, anxiety, and patient satisfaction in patients who present to the emergency department in Turkey
Authors: Parlar Kilic Serap , Karadag Gulendam , Oyucu Serpil , Kale Ozlem , Zengin Suat , Ozdemir Emine , Korhan Esra Akin
Published: March 2014

Aim

The objective of this study is to evaluate the effect of music therapy on pain, anxiety, and patient satisfaction in patients who present to the emergency department in Turkey.

Methods

This controlled and experimental study was conducted in the emergency department of a hospital in Turkey between July and October 2012. The study sample consisted of 200 patients in total, 100 forming the intervention group and 100 being the control group, who fell under color code green in the triage system and came with complaints of pain due to nausea/vomiting and diarrhea, abdominal pain, headaches, and joint pain. A questionnaire, the State Anxiety Scale, and the Visual Analog Scale to measure the patients' level of pain were used in the study. The questionnaires of the intervention group were administered after playing the music.

Results

When the intervention and control groups were compared, it was observed that there was a significant decrease in the VASP and STAI‐S scores in favor of the intervention group. It was observed that 21.0% of the patients in the intervention group were very pleased to hear music in the emergency department, 58% of them were moderately or at least a little pleased, and 21.0% were not pleased at all.

Conclusion

The results showed that music therapy had a positive effect in terms of reducing the severity of pain and the level of anxiety in patients, that only a very small portion of the patients were not pleased to listen to music in the emergency department.
HPC‐1/syntaxin 1A and syntaxin 1B play distinct roles in neuronal survival
Authors: Kofuji Takefumi , Fujiwara Tomonori , Sanada Masumi , Mishima Tatsuya , Akagawa Kimio
Published: March 2014

Two types of syntaxin 1 isoforms, HPC‐1/syntaxin 1A (STX1A) and syntaxin 1B (STX1B), are thought to have similar functions in exocytosis of synaptic vesicles. STX1A−/− mice which we generated previously develop normally, possibly because of compensation by STX1B. We produced STX1B−/− mice using targeted gene disruption and investigated their phenotypes. STX1B−/− mice were born alive, but died before postnatal day 14, unlike STX1A−/− mice. Morphologically, brain development in STX1B−/− mice was impaired. In hippocampal neuronal culture, the cell viability of STX1B−/− neurons was lower than that of WT or STX1A−/− neurons after 9 days. Interestingly, STX1B−/− neurons survived on WT or STX1A−/− glial feeder layers as well as WT neurons. However, STX1B−/− glial feeder layers were less effective at promoting survival of STX1B−/− neurons. Conditioned medium from WT or STX1A−/− glial cells had a similar effect on survival, but that from STX1B−/− did not promote survival. Furthermore, brain‐derived neurotrophic factor (BDNF) or neurotrophin‐3 supported survival of STX1B−/− neurons. BDNF localization in STX1B−/− glial cells was disrupted, and BDNF secretion from STX1B−/− glial cells was impaired. These results suggest that STX1A and STX1B may play distinct roles in supporting neuronal survival by glia.

image

Syntaxin 1A (STX1A) and syntaxin 1B (STX1B) are thought to have similar functions as SNARE proteins. However, we found that STX1A and STX1B play distinct roles in neuronal survival using STX1A−/− mice and STX1B−/− mice. STX1B was important for neuronal survival, possibly by regulating the secretion of neurotrophic factors, such as BDNF, from glial cells.
HIV‐1 protein Tat produces biphasic changes in NMDA‐evoked increases in intracellular Ca2+ concentration via activation of Src kinase and nitric oxide signaling pathways
Authors: Krogh Kelly A. , Wydeven Nicole , Wickman Kevin , Thayer Stanley A.
Published: March 2014

HIV‐associated neurocognitive disorders afflict about half of HIV‐infected patients. HIV‐infected cells shed viral proteins, such as the transactivator of transcription (Tat), which can cause neurotoxicity by over activation of NMDA receptors. Here, we show that Tat causes a time‐dependent, biphasic change in NMDA‐evoked increases in intracellular Ca2+ concentration ([Ca2+]i). NMDA‐evoked responses were potentiated following 2‐h exposure to Tat (50 ng/mL). Tat‐induced potentiation of NMDA‐evoked increases in [Ca2+]i peaked by 8 h and then adapted by gradually reversing to baseline by 24 h and eventually dropping below control by 48 h. Tat‐induced potentiation of NMDA‐evoked responses was blocked by inhibition of lipoprotein receptor‐related protein (LRP) or Src tyrosine kinase. Potentiation was unaffected by inhibition of nitric oxide synthase (NOS). However, NOS activity was required for adaptation. Adaptation was also prevented by inhibition of soluble guanylate cyclase (sGC) and cyclic guanosine monophosphate‐dependent protein kinase G (PKG). Together, these findings indicate that Tat potentiates NMDA‐evoked increases in [Ca2+]i via LRP‐dependent activation of Src and that this potentiation adapts via activation of the NOS/sGC/PKG pathway. Adaptation may protect neurons from excessive Ca2+ influx and could reveal targets for the treatment of HIV‐associated neurocognitive disorders.

image

HIV‐associated neurocognitive disorders (HAND) afflict about half of HIV‐infected patients. HIV‐infected cells shed viral proteins, such as the transactivator of transcription (Tat), which can cause neurotoxicity by over activation of NMDA receptors (NMDARs). We show that HIV‐1 Tat evoked biphasic changes in NMDA‐evoked [Ca2+]i responses. Initially, Tat potentiated NMDA‐evoked responses following LRP‐mediated activation of Src kinase. Subsequently, Tat‐induced NMDAR potentiation adapted by activation of a NOS/sGC/PKG pathway that attenuated NMDA‐evoked increases in [Ca2+]i. Adaptation may be a novel neuroprotective mechanism to prevent excessive Ca2+ influx. Solid and dashed arrows represent direct and potentially indirect connections, respectively.
Measuring Readability in Financial Disclosures
Authors: LOUGHRAN TIM , MCDONALD BILL
Published: March 2014

Defining and measuring readability in the context of financial disclosures becomes important with the increasing use of textual analysis and the Securities and Exchange Commission's plain English initiative. We propose defining readability as the effective communication of valuation‐relevant information. The Fog Index—the most commonly applied readability measure—is shown to be poorly specified in financial applications. Of Fog's two components, one is misspecified and the other is difficult to measure. We report that 10‐K document file size provides a simple readability proxy that outperforms the Fog Index, does not require document parsing, facilitates replication, and is correlated with alternative readability constructs.
The supervisor feedback environment is empowering, but not all the time: Feedback orientation as a critical moderator
Authors: Gabriel Allison S. , Frantz Noelle B. , Levy Paul E. , Hilliard Adam W.
Published: March 2014

Literature on the feedback environment has purported that supportive environments fostered by supervisors lead to improvements in employee well‐being and performance. However, little research has considered how the feedback environment affects workplace motivation or identified boundary conditions of the feedback environment to outcome relationship. The current study extends the literature by utilizing a predictive design to examine how the supervisor feedback environment affects dimensions of employee psychological empowerment (meaning, competence, self‐determination, and impact) after 3 months in a sample of correctional facility employees. Further, we tested how an employee's feedback orientation, or propensity to seek and utilize feedback, attenuated or enhanced the relationship between supervisor feedback environment and empowerment. Results demonstrated that perceptions of the supervisor feedback environment differentially related to each dimension of empowerment, with the feedback environment being a positive predictor of impact and a marginally positive predictor of meaning. Moreover, when feedback orientation was high, the feedback environment exhibited a strong positive relationship with meaning, competence, and self‐determination; when feedback orientation was low, relationships actually became weaker when predicting meaning and negative when predicting competence and self‐determination. The results clarify the scope of impact of the supervisor feedback environment, offering theoretical and practical implications.

Practitioner points

The feedback environment fostered by supervisors can increase employee empowerment.

An employee's feedback orientation is critical in understanding whether the supervisor feedback environment is helpful or harmful for employee empowerment.
Thermal benefits of aggregation in a large marine endotherm: huddling in California sea lions
Authors: Liwanag H. E. M. , Oraze J. , Costa D. P. , Williams T. M.
Published: March 2014

Huddling is an important behavior for many endotherms, and it is associated with both social interactions and physiological regulation. Sea lions are highly communal pinnipeds that often congregate in large numbers on coastal rookeries. While this behavior serves a social role, it also has the potential to change the microhabitat and thus the local thermal conditions experienced by the animals. However, the thermal consequences of huddling in pinnipeds have yet to be quantified despite a propensity for close proximity in some species. To investigate this, we quantified the huddling behavior of California sea lions, Zalophus californianus, by measuring the proximity of individuals from digital photographs, and determined the thermal microhabitat of huddles using an infrared temperature monitor. All animals were measured on San Nicolas Island (California, USA) for 6 days in winter (Tair = 13.2 ± 2.1°C) and 7 days in summer (Tair = 21.1 ± 3.4°C). We found that sea lion huddling behavior increased in colder weather, as determined from three indices. First, a larger proportion (up to 97%) of the animals participated in huddles rather than resting alone during the winter season (P = 0.010). Second, the number of animals per huddle was larger (reaching 172 animals) during the colder season (P = 0.019). Lastly, sea lions participating in this behavior huddled more tightly in cold temperatures (P = 0.023). The temperature differential between the animals' skin surface and that of the surrounding substrate was significantly greater (P < 0.001) for huddling sea lions (6.0 ± 3.6°C) than for animals resting alone (3.0 ± 2.8°C). Furthermore, this differential was inversely proportional to ambient temperatures. These results are consistent with huddling behavior in California sea lions providing a significant thermal benefit that likely shapes their social behavior on land.
Stuck in the middle with you: close concordance between geographical clines in a cricket hybrid zone
Authors: Vines Timothy H.
Published: March 2014

Students of speciation have long recognized that hybridization between populations does not affect all parts of the genome in the same way (Key 1968, Bazykin 1969, Wu 2001, Nosil et al. 2009). For example, divergence is expected to be high at loci involved in Dobzhansky–Muller incompatibilities or at loci under divergent natural selection, while those that are effectively neutral should show only weak divergence. Studies that examine geographical clines at divergent loci in a hybrid zone can be particularly powerful, as here one can estimate how net selection is affecting each locus (Payseur 2010). An excellent example of this approach appears in this issue (Larson et al. 2014) for a hybrid zone between the crickets Gryllus firmus and Gryllus pennsylvanicus in the eastern United States.
The shape of things to come in the study of the origin of species?
Authors: Rogers Sean M. , Jamniczky Heather A.
Published: March 2014

Perhaps Darwin would agree that speciation is no longer the mystery of mysteries that it used to be. It is now generally accepted that evolution by natural selection can contribute to ecological adaptation, resulting in the evolution of reproductive barriers and, hence, to the evolution of new species (Schluter & Conte ; Meyer ; Nosil ). From genes that encode silencing proteins that cause infertility in hybrid mice (Mihola et al. ), to segregation distorters linked to speciation in fruit flies (Phadnis & Orr ), or pollinator‐mediated selection on flower colour alleles driving reinforcement in Texan wildflowers (Hopkins & Rausher ), characterization of the genes that drive speciation is providing clues to the origin of species (Nosil & Schluter ). It is becoming apparent that, while recent work continues to overturn historical ideas about sympatric speciation (e.g. Barluenga et al. ), ecological circumstances strongly influence patterns of genomic divergence, and ultimately the establishment of reproductive isolation when gene flow is present (Elmer & Meyer ). Less clear, however, are the genetic mechanisms that cause speciation, particularly when ongoing gene flow is occurring. Now, in this issue, Franchini et al. () employ a classic genetic mapping approach augmented with new genomic tools to elucidate the genomic architecture of ecologically divergent body shapes in a pair of sympatric crater lake cichlid fishes. From over 450 segregating SNPs in an F2 cross, 72 SNPs were linked to 11 QTL associated with external morphology measured by means of traditional and geometric morphometrics. Annotation of two highly supported QTL further pointed to genes that might contribute to ecological divergence in body shape in Midas cichlids, overall supporting the hypothesis that genomic regions of large phenotypic effect may be contributing to early‐stage divergence in Midas cichlids.
Predator–prey trophic relationships in response to organic management practices
Authors: Schmidt Jason M. , Barney Sarah K. , Williams Mark A. , Bessin Ricardo T. , Coolong Timothy W. , Harwood James D.
Published: March 2014

A broad range of environmental conditions likely regulate predator–prey population dynamics and impact the structure of these communities. Central to understanding the interplay between predator and prey populations and their importance is characterizing the corresponding trophic interactions. Here, we use a well‐documented molecular approach to examine the structure of the community of natural enemies preying upon the squash bug, Anasa tristis, a herbivorous cucurbit pest that severely hinders organic squash and pumpkin production in the United States. Primer pairs were designed to examine the effects of organic management practices on the strength of these trophic connections and link this metric to measures of the arthropod predator complex density and diversity within an experimental open‐field context. Replicated plots of butternut squash were randomly assigned to three treatments and were sampled throughout a growing season. Row‐cover treatments had significant negative effects on squash bug and predator communities. In total, 640 predators were tested for squash bug molecular gut‐content, of which 11% were found to have preyed on squash bugs, but predation varied over the season between predator groups (coccinellids, geocorids, nabids, web‐building spiders and hunting spiders). Through the linking of molecular gut‐content analysis to changes in diversity and abundance, these data delineate the complexity of interaction pathways on a pest that limits the profitability of organic squash production.
The advantages of going large: genome‐wide SNPs clarify the complex population history and systematics of the threatened western pond turtle
Authors: Spinks Phillip Q. , Thomson Robert C. , Shaffer H. Bradley
Published: March 2014

As the field of phylogeography has matured, it has become clear that analyses of one or a few genes may reveal more about the history of those genes than the populations and species that are the targets of study. To alleviate these concerns, the discipline has moved towards larger analyses of more individuals and more genes, although little attention has been paid to the qualitative or quantitative gains that such increases in scale and scope may yield. Here, we increase the number of individuals and markers by an order of magnitude over previously published work to comprehensively assess the phylogeographical history of a well‐studied declining species, the western pond turtle (Emys marmorata). We present a new analysis of 89 independent nuclear SNP markers and one mitochondrial gene sequence scored for rangewide sampling of >900 individuals, and compare these to smaller‐scale, rangewide genetic and morphological analyses. Our enlarged SNP data fundamentally revise our understanding of evolutionary history for this lineage. Our results indicate that the gains from greatly increasing both the number of markers and individuals are substantial and worth the effort, particularly for species of high conservation concern such as the pond turtle, where accurate assessments of population history are a prerequisite for effective management.
Bacillus subtilis spore protein SpoVAC functions as a mechanosensitive channel
Authors: Velásquez Jeanette , Schuurman‐Wolters Gea , Birkner Jan Peter , Abee Tjakko , Poolman Bert
Published: March 2014

A critical event during spore germination is the release of Ca‐DPA (calcium in complex with dipicolinic acid). The mechanism of release of Ca‐DPA through the inner membrane of the spore is not clear, but proteins encoded by the Bacillus subtilis spoVA operon are involved in the process. We cloned and expressed the spoVAC gene in Escherichia coli and characterized the SpoVAC protein. We show that SpoVAC protects E. coli against osmotic downshift, suggesting that it might act as a mechanosensitive channel. Purified SpoVAC was reconstituted in unilamellar lipid vesicles to determine the gating mechanism and pore properties of the protein. By means of a fluorescence‐dequenching assay, we show that SpoVAC is activated upon insertion into the membrane of the amphiphiles lysoPC and dodecylamine. Patch clamp experiments on E. coli giant spheroplast as well as giant unilamellar vesicles (GUVs) containing SpoVAC show that the protein forms transient pores with main conductance values of about 0.15 and 0.1 nS respectively. Overall, our data indicate that SpoVAC acts as a mechanosensitive channel and has properties that would allow the release of Ca‐DPA and amino acids during germination of the spore.
TCA cycle activity in Staphylococcus aureus is essential for iron‐regulated synthesis of staphyloferrin A, but not staphyloferrin B: the benefit of a second citrate synthase
Authors: Sheldon Jessica R. , Marolda Cristina L. , Heinrichs David E.
Published: March 2014

Staphylococcus aureus elaborates two citrate‐containing siderophores, staphyloferrin A (SA) and staphyloferrin B (SB), that enhance growth under iron‐restriction, yet, paradoxically, expression of the TCA cycle citrate synthase, CitZ, is downregulated during iron starvation. Iron starvation does, however, result in expression of SbnG, recently identified as a novel citrate synthase that is encoded from within the iron‐regulated SB biosynthetic locus, suggesting an important role for SbnG in staphyloferrin production. We demonstrate that during growth of S. aureus in iron‐restricted media containing glucose, SB is produced but, in contrast, SA production is severely repressed; accordingly, SB‐deficient mutants grow poorly in these media. Hypothesizing that reduced TCA cycle activity hinders SA production, we show that a citZ mutant is capable of SB synthesis, but not SA synthesis, providing evidence that SbnG does not generate citrate for incorporation into SA. A citZ sbnG mutant synthesizes neither staphyloferrin, is severely compromised for growth in iron‐restricted media, and is significantly more impaired for virulence than either of the single‐deletion mutants. We propose that SB is the more important of the two siderophores for S. aureus insofar as it is synthesized, and supports iron‐restricted growth, without need of TCA cycle activity.
Metal specificity of cyanobacterial nickel‐responsive repressor InrS: cells maintain zinc and copper below the detection threshold for InrS
Authors: Foster Andrew W. , Pernil Rafael , Patterson Carl J. , Robinson Nigel J.
Published: March 2014

InrS is a Ni(II)‐responsive, CsoR/RcnR‐like, DNA‐binding transcriptional repressor of the nrsD gene, but the Ni(II) co‐ordination sphere of InrS is unlike Ni(II)‐RcnR. We show that copper and Zn(II) also bind tightly to InrS and in vitro these ions also impair InrS binding to the nrsD operator‐promoter. InrS does not respond to Zn(II) (or copper) in vivo after 48 h, when Zn(II) sensor ZiaR responds, but InrS transiently responds (1 h) to both metals. InrS conserves only one (of two) second co‐ordination shell residues of CsoR (Glu98 in InrS). The allosteric mechanism of InrS is distinct from Cu(I)‐CsoR and conservation of deduced second shell residues better predicts metal specificity than do the metal ligands. The allosteric mechanism of InrS permits greater promiscuity in vitro than CsoR. The factors dictating metal‐selectivity in vivo are that KNi(II) and ΔGCNi(II)‐InrS·DNA are sufficiently high, relative to other metal sensors, for InrS to detect Ni(II), while the equivalent parameters for copper may be insufficient for copper‐sensing in Synechocystis (at 48 h). InrS KZn(II) (5.6 × 10−13 M) is comparable to the sensory sites of ZiaR (and Zur), but ΔGCZn(II)‐InrS·DNA is less than ΔGCZn(II)‐ZiaR·DNA implying that relative to other sensors, ΔGCZn(II)‐Sensor·DNA rather than KZn(II) determines the final detection threshold for Zn(II).
Ceropegia suddeei sp. nov. (Apocynaceae, Asclepiadoideae) from northeastern Thailand
Authors: Kidyoo Manit
Published: March 2014

Ceropegia suddeei Kidyoo is a new species discovered in the Phu Phan National Park, northeastern Thailand. Taxonomic description, illustrations of this new species and a comparison with the related species C. thailandica Meve. are presented.
The vitamin D receptor turns off chronically activated T cells
Authors: Cantorna Margherita T. , Waddell Amanda
Published: March 2014

T cell proliferation and T helper (TH) cells that make IL‐17 (TH17 cells) and IFN‐γ (TH1 cells) have been shown to be inhibited by 1,25(OH)2D3. Previous work has shown that immune‐mediated diseases, where TH1 and TH17 cells are pathogenic, are ameliorated with 1,25(OH)2D3 treatment. Paradoxically, infectious diseases that require TH1 and TH17 responses for host resistance are unaffected by 1,25(OH)2D3 treatment. Resting T cells are not responsive to vitamin D because they do not express the vitamin D receptor (VDR) until late after activation. T cells activated following an infection help clear the infection, and since the antigen is eliminated, vitamin D is not needed to dampen the immune response. Conversely, in immune‐mediated disease, there is chronic T cell activation, and in this scenario, vitamin D and 1,25(OH)2D3 are critical for inhibiting T cell proliferation and cytokine production. Vitamin D is a late regulator of T cell function and acts to turn off T cells. This paper will review these data.
Meta‐analysis results are unlikely to be biased by differences in variance and replication between ecological lab and field studies
Authors: Hillebrand Helmut , Gurevitch Jessica
Published: March 2014

A recurrent question in meta‐analyses is the validity of including both field and laboratory studies in a single analysis, given the differences in characteristics such as the duration or size of these experiments. In particular, are field studies consistently more variable, longer in duration, or do they differ from laboratory studies in other important ways? We examined these questions using an unusually large and comprehensive data set on grazing effects on benthic microalgae, consisting of 865 experiments including both field and lab studies and using marine, lotic or lentic communities of small benthic primary producers. We found there was greater variation in field than laboratory studies, but that this difference explained only 0.5% of the variance in the coefficient of variation. Field studies were longer, on average, than laboratory studies, but experiments in the two systems did not differ consistently in other ecological or design parameters. Thus, the common assumption that field studies have higher variances than laboratory studies, while true, explained only a tiny proportion of the heterogeneity in variation. Therefore, perhaps surprisingly, any conclusions from research syntheses would be unlikely to be affected by consistent differences in variance (or other parameters we examined) between the laboratory and field studies.
Variability in Clinical Features of Early Versus Late Cardiovascular Implantable Electronic Device Pocket Infections
Authors: WELCH MARIKO , USLAN DANIEL Z. , GREENSPON ARNOLD J. , SOHAIL MUHAMMAD R. , BADDOUR LARRY M. , BLANK ELISABETH , CARRILLO ROGER G. , DANIK STEPHAN B. , DEL RIO ANA , HELLINGER WALTER , LE KATHERINE Y. , MIRO JOSE M. , NABER CHRISTOPH , PEACOCK JAMES E. , VIKRAM HOLENARASIPUR R. , TSENG CHI‐HONG , PRUTKIN JORDAN M. ,   for the MEDIC Investigators
Published: March 2014

Background

Cardiovascular implantable electronic device (CIED) pocket infections are often related to recent CIED placement or manipulation, but these infections are not well characterized. The clinical presentation of CIED pocket infection, based on temporal onset related to last CIED procedure, deserves further study.

Methods

The MEDIC (Multicenter Electrophysiologic Device Infection Cohort) prospectively enrolled subjects with CIED infection. Subjects were stratified into those whose infection occurred <12 months (early) or ≥12 months (late) since their last CIED‐related procedure.

Results

There were 132 subjects in the early group and 106 in the late group. There were more females (P = 0.009) and anticoagulation use (P = 0.039) in the early group. Subjects with early infections were more likely to have had a generator change or lead addition as their last procedure (P = 0.03) and had more prior CIED procedures (P = 0.023). Early infections were more likely to present with pocket erythema (P < 0.001), swelling (P < 0.001), and pain (P = 0.007). Late infections were more likely to have pocket erosion (P = 0.005) and valvular vegetations (P = 0.009). In bacteremic subjects, early infections were more likely healthcare‐associated (P < 0.001). In‐hospital and 6‐month mortality were equivalent.

Conclusion

A total of 45% of patients with CIED pocket infection presented >12 months following their last CIED‐related procedure. Patients with early infection were more likely to be female, on anticoagulation, and present with localized inflammation, whereas those with late infection were more likely to have CIED erosion or valvular endocarditis.
Symptomatic and Asymptomatic Long‐Term Recurrences Following Transcatheter Atrial Fibrillation Ablation
Authors: MANGANIELLO SABRINA , ANSELMINO MATTEO , AMELLONE CLAUDIA , PELISSERO ELISA , GIUGGIA MARCO , TRAPANI GIUSEPPE , GIORDANO BENEDETTA , SENATORE GAETANO , GAITA FIORENZO
Published: March 2014

Background

Atrial fibrillation (AF) relapses, following transcatheter AF ablation, are frequently reported based on patients’ symptoms, scheduled electrocardiograms (ECGs), or 24‐hour Holter recordings. The aim of this study is to determine the incidence of asymptomatic and symptomatic AF recurrences, using continuous subcutaneous ECG monitoring, in the long‐term follow‐up of patients with paroxysmal or persistent AF undergoing transcatheter ablation.

Methods and Results

In total 113 consecutive patients symptomatic for paroxysmal or persistent AF were enrolled. All patients underwent pulmonary vein isolation plus left linear lesions. The insertable cardiac monitor (ICM), subcutaneously implanted during the ablation procedure, recorded the amount of AF per day (daily burden) and per last follow‐up period (total AF burden). Based on symptoms and on scheduled 12‐lead ECG performed during follow‐up, 40 patients (35.4%) suffered AF recurrences. By means of ICM data, however, arrhythmia relapses were recorded within 75 patients (66.3%), of whom 35 (46.7%) were asymptomatic. Patients suffering symptomatic AF recurrences resulted, at univariate analysis, older (66.6 ± 8.4 years vs 61.6 ± 10.7 years) and suffering greater AF burden (88.8 ± 26.9% vs 8.0 ± 8.0%).

Conclusions

AF ablation outcome based on patients’ symptoms and/or scheduled ECGs underestimated relapses, as up to half of the patients, during a long‐term follow‐up, suffer asymptomatic recurrences.