bluuebunny/crossref_metadata_2025_split huggingface dataset:
Malacological survey and geographical distribution of vector snails for schistosomiasis within informal settlements of Kisumu City, western Kenya
Authors: Opisa Selpha , Odiere Maurice R , Jura Walter GZO , Karanja Diana MS , Mwinzi Pauline NM 
Published: December 2011

Abstract

Background
Although schistosomiasis is generally considered a rural phenomenon, infections have been reported within urban settings. Based on observations of high prevalence of Schistosoma mansoni infection in schools within the informal settlements of Kisumu City, a follow-up malacological survey incorporating 81 sites within 6 informal settlements of the City was conducted to determine the presence of intermediate host snails and ascertain whether active transmission was occurring within these areas.

Methods
Surveyed sites were mapped using a geographical information system. Cercaria shedding was determined from snails and species of snails identified based on shell morphology. Vegetation cover and presence of algal mass at the sites was recorded, and the physico-chemical characteristics of the water including pH and temperature were determined using a pH meter with a glass electrode and a temperature probe.

Results
Out of 1,059 snails collected, 407 (38.4%) were putatively identified as Biomphalaria sudanica, 425 (40.1%) as Biomphalaria pfeifferi and 227 (21.5%) as Bulinus globosus. The spatial distribution of snails was clustered, with few sites accounting for most of the snails. The highest snail abundance was recorded in Nyamasaria (543 snails) followed by Nyalenda B (313 snails). As expected, the mean snail abundance was higher along the lakeshore (18 ± 12 snails) compared to inland sites (dams, rivers and springs) (11 ± 32 snails) (F1, 79 = 38.8, P < 0.0001). Overall, 19 (1.8%) of the snails collected shed schistosome cercariae. Interestingly, the proportion of infected Biomphalaria snails was higher in the inland (2.7%) compared to the lakeshore sites (0.3%) (P = 0.0109). B. sudanica was more abundant in sites along the lakeshore whereas B. pfeifferi and B. globosus were more abundant in the inland sites. Biomphalaria and Bulinus snails were found at 16 and 11 out of the 56 inland sites, respectively.

Conclusions
The high abundance of Biomphalaria and Bulinus spp. as well as observation of field-caught snails shedding cercariae confirmed that besides Lake Victoria, the local risk for schistosomiasis transmission exists within the informal settlements of Kisumu City. Prospective control interventions in these areas need to incorporate focal snail control to complement chemotherapy in reducing transmission.
Parasites of vectors - Ixodiphagus hookeri and its Wolbachia symbionts in ticks in the Netherlands
Authors: Tijsse-Klasen Ellen , Braks Marieta , Scholte Ernst-Jan , Sprong Hein 
Published: December 2011

Abstract

Background

Ixodiphagus hookeri is a parasitic wasp of ixodid ticks around the world. It has been studied as a potential bio-control agent for several tick species. We suspected that the presence of Wolbachia infected I. hookeri eggs in ticks is responsible for incidental detection of Wolbachia DNA in tick samples.

Methods
The 28S rRNA and 16S rRNA genes of a specimen of I. hookeri was amplified and sequenced. PCR on part of the 28S rRNA gene was used to detect parasitic wasp DNA in 349 questing Ixodes ricinus ticks from various sampling sites. Furthermore, the wsp gene of Wolbachia was sequenced from the I. hookeri specimen and a subset of ticks was tested using this marker.

Results
Several sequences from tick specimens were identical to the Wolbachia sequence of the I. hookeri specimen. Ixodiphagus hookeri was detected in 9.5% of all tested ticks, varying between 4% and 26% depending on geographic location. Ten out of eleven sampling sites throughout the Netherlands were positive for I. hookeri. Eighty-seven percent of I. hookeri- positive but only 1.6% of I. hookeri-negative ticks were Wolbachia positive. Detection of I. hookeri DNA was strongly associated with the detection of Wolbachia in ticks.

Conclusion
This is the first reported case of I. hookeri in the Netherlands. Furthermore I. hookeri harbours Wolbachia species and is broadly distributed in the Netherlands. While detection of Wolbachia DNA in ticks might often be due to parasitism with this wasp, other sources of Wolbachia DNA in ticks might exist as well.
Opposing roles of CXCR4 and CXCR7 in breast cancer metastasis
Authors: Hernandez Lorena , Magalhaes Marco AO , Coniglio Salvatore J , Condeelis John S , Segall Jeffrey E 
Published: December 2011

Abstract
Introduction
CXCL12-CXCR4 signaling has been shown to play a role in breast cancer progression by enhancing tumor growth, angiogenesis, triggering cancer cell invasion in vitro, and guiding cancer cells to their sites of metastasis. However, CXCR7 also binds to CXCL12 and has been recently found to enhance lung and breast primary tumor growth, as well as metastasis formation. Our goal was to dissect the contributions of CXCR4 and CXCR7 to the different steps of metastasis - in vivo invasion, intravasation and metastasis formation.

Methods
We overexpressed CXCR4, CXCR7 or both in the rat mammary adenocarcinoma cell line MTLn3. Stable expressors were used to form tumors in severe combined immunodeficiency (SCID) mice, and in vivo invasiveness, intravital motility, intravasation, and metastasis were measured.

Results
We found that CXCR4 overexpression increased the chemotactic and invasive behavior of MTLn3 cells to CXCL12, both in vitro and in vivo, as well as in vivo motility and intravasation. CXCR7 overexpression enhanced primary tumor growth and angiogenesis (as indicated by microvessel density and VEGFA expression), but decreased in vivo invasion, intravasation, and metastasis formation. In vitro, expression of CXCR7 alone had no effect in chemotaxis or invasion to CXCL12. However, in the context of increased CXCR4 expression, CXCR7 enhanced chemotaxis to CXCL12 but decreased invasion in response to CXCL12 in vitro and in vivo and impaired CXCL12 stimulated matrix degradation. The changes in matrix degradation correlated with expression of matrix metalloproteinase 12 (MMP12).

Conclusions
We find that CXCR4 and CXCR7 play different roles in metastasis, with CXCR4 mediating breast cancer invasion and CXCR7 impairing invasion but enhancing primary tumor growth through angiogenesis.
Selected regulation of gastrointestinal acid–base secretion and tissue metabolism for the diamondback water snake and Burmese python
Authors: Secor Stephen M. , Taylor Josi R. , Grosell Martin 
Published: December 2011

SUMMARY
Snakes exhibit an apparent dichotomy in the regulation of gastrointestinal (GI) performance with feeding and fasting; frequently feeding species modestly regulate intestinal function whereas infrequently feeding species rapidly upregulate and downregulate intestinal function with the start and completion of each meal, respectively. The downregulatory response with fasting for infrequently feeding snakes is hypothesized to be a selective attribute that reduces energy expenditure between meals. To ascertain the links between feeding habit, whole-animal metabolism, and GI function and metabolism, we measured preprandial and postprandial metabolic rates and gastric and intestinal acid–base secretion, epithelial conductance and oxygen consumption for the frequently feeding diamondback water snake (Nerodia rhombifer) and the infrequently feeding Burmese python (Python molurus). Independent of body mass, Burmese pythons possess a significantly lower standard metabolic rate and respond to feeding with a much larger metabolic response compared with water snakes. While fasting, pythons cease gastric acid and intestinal base secretion, both of which are stimulated with feeding. In contrast, fasted water snakes secreted gastric acid and intestinal base at rates similar to those of digesting snakes. We observed no difference between fasted and fed individuals for either species in gastric or intestinal transepithelial potential and conductance, with the exception of a significantly greater gastric transepithelial potential for fed pythons at the start of titration. Water snakes experienced no significant change in gastric or intestinal metabolism with feeding. Fed pythons, in contrast, experienced a near-doubling of gastric metabolism and a tripling of intestinal metabolic rate. For fasted individuals, the metabolic rate of the stomach and small intestine was significantly lower for pythons than for water snakes. The fasting downregulation of digestive function for pythons is manifested in a depressed gastric and intestinal metabolism, which selectively serves to reduce basal metabolism and hence promote survival between infrequent meals. By maintaining elevated GI performance between meals, fasted water snakes incur the additional cost of tissue activity, which is expressed in a higher standard metabolic rate.
Interactive effects of salinity and elevated CO2 levels on juvenile eastern oysters,Crassostrea virginica
Authors: Dickinson Gary H. , Ivanina Anna V. , Matoo Omera B. , Pörtner Hans O. , Lannig Gisela , Bock Christian , Beniash Elia , Sokolova Inna M. 
Published: December 2011

SUMMARYRising levels of atmospheric CO2 lead to acidification of the ocean and alter seawater carbonate chemistry, which can negatively impact calcifying organisms, including mollusks. In estuaries, exposure to elevated CO2 levels often co-occurs with other stressors, such as reduced salinity, which enhances the acidification trend, affects ion and acid–base regulation of estuarine calcifiers and modifies their response to ocean acidification. We studied the interactive effects of salinity and partial pressure of CO2 (PCO2) on biomineralization and energy homeostasis in juveniles of the eastern oyster, Crassostrea virginica, a common estuarine bivalve. Juveniles were exposed for 11 weeks to one of two environmentally relevant salinities (30 or 15 PSU) either at current atmospheric PCO2 (∼400 μatm, normocapnia) or PCO2 projected by moderate IPCC scenarios for the year 2100 (∼700–800 μatm, hypercapnia). Exposure of the juvenile oysters to elevated PCO2 and/or low salinity led to a significant increase in mortality, reduction of tissue energy stores (glycogen and lipid) and negative soft tissue growth, indicating energy deficiency. Interestingly, tissue ATP levels were not affected by exposure to changing salinity and PCO2, suggesting that juvenile oysters maintain their cellular energy status at the expense of lipid and glycogen stores. At the same time, no compensatory upregulation of carbonic anhydrase activity was found under the conditions of low salinity and high PCO2. Metabolic profiling using magnetic resonance spectroscopy revealed altered metabolite status following low salinity exposure; specifically, acetate levels were lower in hypercapnic than in normocapnic individuals at low salinity. Combined exposure to hypercapnia and low salinity negatively affected mechanical properties of shells of the juveniles, resulting in reduced hardness and fracture resistance. Thus, our data suggest that the combined effects of elevated PCO2 and fluctuating salinity may jeopardize the survival of eastern oysters because of weakening of their shells and increased energy consumption.
Electromyography of wrist and finger flexor muscles in olive baboons (Papio anubis)
Authors: Patel Biren A. , Larson Susan G. , Stern Jack T. 
Published: December 2011

SUMMARYSome non-human primates use digitigrade hand postures when walking slowly on the ground. As a component of an extended limb, a digitigrade posture can help minimize wrist joint moments thereby requiring little force production directly from wrist flexors (and/or from the assistance of finger flexors) to maintain limb posture. As a consequence, less active muscle volume would be required from these anti-gravity muscles and overall metabolic costs associated with locomotion could be reduced. To investigate whether the use of digitigrade hand postures during walking in primates entails minimal use of anti-gravity muscles, this study examined electromyography (EMG) patterns in both the wrist and finger flexor muscles in facultatively digitigrade olive baboons (Papio anubis) across a range of speeds. The results demonstrate that baboons can adopt a digitigrade hand posture when standing and moving at slow speeds without requiring substantial EMG activity from distal anti-gravity muscles. Higher speed locomotion, however, entails increasing EMG activity and is accompanied by a dynamic shift to a more palmigrade-like limb posture. Thus, the ability to adopt a digitigrade hand posture by monkeys is an adaptation for ground living, but it was never co-opted for fast locomotion. Rather, digitigrady in primates appears to be related to energetic efficiency for walking long distances.
Vocal tract articulation revisited: the case of the monk parakeet
Authors: Ohms Verena R. , Beckers Gabriël J. L. , ten Cate Carel , Suthers Roderick A. 
Published: December 2011

SUMMARYBirdsong and human speech share many features with respect to vocal learning and development. However, the vocal production mechanisms have long been considered to be distinct. The vocal organ of songbirds is more complex than the human larynx, leading to the hypothesis that vocal variation in birdsong originates mainly at the sound source, while in humans it is primarily due to vocal tract filtering. However, several recent studies have indicated the importance of vocal tract articulators such as the beak and oropharyngeal–esophageal cavity. In contrast to most other bird groups, parrots have a prominent tongue, raising the possibility that tongue movements may also be of significant importance in vocal production in parrots, but evidence is rare and observations often anecdotal. In the current study we used X-ray cinematographic imaging of naturally vocalizing monk parakeets (Myiopsitta monachus) to assess which articulators are possibly involved in vocal tract filtering in this species. We observed prominent tongue height changes, beak opening movements and tracheal length changes, which suggests that all of these components play an important role in modulating vocal tract resonance. Moreover, the observation of tracheal shortening as a vocal articulator in live birds has to our knowledge not been described before. We also found strong positive correlations between beak opening and amplitude as well as changes in tongue height and amplitude in several types of vocalization. Our results suggest considerable differences between parrot and songbird vocal production while at the same time the parrot's vocal articulation might more closely resemble human speech production in the sense that both make extensive use of the tongue as a vocal articulator.
Association of AKI with Adverse Outcomes in Burned Military Casualties
Authors: Stewart Ian J. , Tilley Molly A. , Cotant Casey L. , Aden James K. , Gisler Christopher , Kwan Hana K. , McCorcle Jeffery , Renz Evan M. , Chung Kevin K. 
Published: December 2011

Summary

Background and objectives
Although associated with increased morbidity and mortality, AKI has not been systematically examined in military personnel injured from combat operations in Iraq and Afghanistan.

Design, settings, participants, & measurements
Patients evacuated from Iraq and Afghanistan to a burn unit were examined. AKI was classified by the Acute Kidney Injury Network (AKIN) and Risk-Injury-Failure-Loss-End Stage (RIFLE) schemas. Age, sex, percentage of total body surface area burned (TBSA), percentage of full-thickness burn, inhalation injury, and injury severity score were recorded. Additional data that could be associated with poor outcomes were recorded for patients with TBSA ≥20%. Multivariate logistic regression analyses were performed to determine factors associated with morbidity and mortality.

Results
AKI prevalence rates by the RIFLE and AKIN criteria were 23.8% and 29.9%, respectively. After logistic regression, RIFLE categories of risk (odds ratio [OR], 15.34; 95% confidence interval [CI], 1.75–134; P=0.01), injury (OR, 46.28; 95% CI, 5.02–427; P<0.001), and failure (OR, 126; 95% CI, 13.39–>999; P<0.001); AKIN-2 (OR, 23.70; 95% CI, 2.32–242; P=0.008); and AKIN-3 (OR, 130; 95% CI, 13.38–>999; P<0.001) were significantly associated with death. AKIN-3, injury, and failure remained significant in the subset of patients with ≥20% TBSA. There was also a strong interaction between TBSA and the stage of AKI with respect to ventilator and intensive care unit days.

Conclusions
AKI is prevalent in military casualties with burn injury and is independently associated with morbidity and mortality after adjustment for factors associated with injury severity.
Impact of Structure of Early Practice on Student Performance in Transaction Analysis
Authors: Johnson Benny G. , Slayter Erik 
Published: December 2011

ABSTRACT
In introductory accounting textbooks, virtually all end-of-chapter problems on transaction analysis follow the same familiar format: a collection of transactions performed by a given business during a specified time period. Modern research-based models of human cognitive architecture suggest, however, that this format is suboptimal for beginning students. An approach better aligned with this learning research would give students practice with one transaction type at a time before proceeding to problems involving a mixture of transaction types. An experiment was conducted to test this hypothesis by randomly assigning students in an introductory financial accounting course to one of two practice conditions: conventional textbook problems and “targeted practice” in which the same transactions were grouped by type. All students were then given a conventional textbook problem as a post-test. During the practice phase, students in the targeted practice group analyzed transactions in less time and with greater accuracy than students who worked conventional problems. On the post-test, the total scores of the two groups were statistically equivalent; thus, the targeted practice group achieved the same level of performance more efficiently. However, on transactions requiring transfer of learning, the targeted practice group performed notably better, indicating these students were better able to apply knowledge gained during practice to a broad variety of transaction scenarios. The implications of this study are straightforward and practical: by making a very simple modification to the format of transaction analysis problems given to students early in the learning process, better learning outcomes can be obtained.
The Financial Statement Interview: Intentional Learning in the First Accounting Course
Authors: Killian Larita J. , Huber Marsha M. , Brandon Christopher D. 
Published: December 2011

ABSTRACT
The first accounting course should do more than equip students with technical knowledge and skills. It should also engender respect for the accounting profession and help students explore accounting-related careers. Above all, it should help students develop intentional learning skills and become life-long learners. To help students achieve these goals, we developed an exercise that incorporates the five-part intentional learning model created by Francis et al. (1995). Students identify a professional to interview about the uses and limitations of financial statements, conduct the interview, and then reflect on the experience using an instrument with reflective prompts.
In this paper we discuss our motivation for the exercise, review the literature that guided our use of the exercise, and use qualitative research techniques to assess its effectiveness for achieving objectives of the first course. We conclude that the exercise is highly effective in helping students achieve intentional learning in the first accounting course and in promoting respect for the profession. It is effective in helping students identify accounting-related careers, but less effective in prompting them to consider the suitability of such careers for themselves. We provide recommendations to improve the exercise and address potential concerns that instructors may face as they implement this effective learning strategy.
Industry Perspective Workshop Program: An Instructional Case Used to Integrate Transferable Skills in Introductory Accounting
Authors: McGuigan Nicholas , Weil Sidney H. , Kern Thomas , Hu Baiding 
Published: December 2011

ABSTRACT
The professional environment in which accountants operate has, in recent years, become increasingly complex, leading to significant changes within the profession. Intensifying the need for this change are the pressures associated with the recent global financial crisis, changes in information and communication technology, and the continuous introduction of new accounting standards. Employers are calling for the increased development of “non-technical” skills, such as critical thinking and the ability to communicate and engage with clients, within current graduates in order to meet the needs of the evolving and dynamic profession (Kavanagh and Drennan 2008; Hancock et al. 2010). In order for this to occur, real integration of non-technical skills' development into the accounting curriculum needs to take place. This instructional case tries to achieve this, providing students with an opportunity to apply theoretical accounting concepts to the creation of their own business, while actively developing their group processing skills. The primary objective of the case is to provide students with an opportunity to acquire technical accounting skills concurrently with group processing skills and other non-technical skills. A secondary objective of the case is to encourage students to engage with the technical learning material in the introductory accounting curriculum. This paper describes the design of an Industry Perspective Workshop Program that incorporates the comprehensive integration of group processing skills and accounting-related content within an introductory accounting decision-making course.
Schreier type theorems for bicrossed products
Authors: Agore Ana , Militaru Gigel 
Published: December 2011

Abstract
We prove that the bicrossed product of two groups is a quotient of the pushout of two semidirect products. A matched pair of groups (H;G; α; β) is deformed using a combinatorial datum (σ; v; r) consisting of an automorphism σ of H, a permutation v of the set G and a transition map r: G → H in order to obtain a new matched pair (H; (G; *); α′, β′) such that there exists a σ-invariant isomorphism of groups H
α⋈β
G ≅H
α′⋈β′ (G, *). Moreover, if we fix the group H and the automorphism σ ∈ Aut H then any σ-invariant isomorphism H
α⋈β
G ≅ H
α′⋈β′
G′ between two arbitrary bicrossed product of groups is obtained in a unique way by the above deformation method. As applications two Schreier type classification theorems for bicrossed products of groups are given.