bluuebunny/crossref_metadata_2025_split huggingface dataset:
Population size, catchment area, and sex-influenced differences in autumn and spring swarming of the brown long-eared bat (Plecotus auritus)
Authors: Furmankiewicz J. 
Published: April 2008

Swarming by bats is defined as intense autumnal flight activity in and near underground hibernation sites and is considered to be associated with mating, but this behaviour may also serve to allow bats to assess potential hibernacula. To test if swarms consist of resident bat populations from the surrounding area or transitional bat populations migrating between summer and winter areas, I measured activity patterns and the distribution of day roosts of swarming brown long-eared bats ( Plecotus auritus (L., 1758)) at two abandoned mines in southwestern Poland. Swarming occurred from mid-August to mid-October, and also in March and April. The maximum population of swarming bats was estimated to be about 500 individuals. The sex ratio was male-biased and was more skewed in spring than in autumn. Bats frequently travelled to the swarming site from day roosts as far away as 31.5 km. They usually stayed for several hours before returning to a day roost without visiting other hibernacula. Males roosted closer to the swarming site and visited it more frequently than females, consistent with increased mating attempts. My results suggest that swarming sites are hot spots for populations resident in the surrounding area. They likely play an important role in gene flow and facilitate mating among bats from spatially isolated populations.
Spatial and temporal patterns of territory use of male California sea lions (Zalophus californianus) in the Gulf of California, Mexico
Authors: Robertson Kathy L. , Runcorn C. W. , Young Julie K. , Gerber Leah R. 
Published: April 2008

Little is known about the spatial distribution patterns of territory use throughout the breeding season and the potential influence of these patterns on male behavior and fitness for California sea lions ( Zalophus californianus (Lesson, 1828)). We used empirical data from behavioral observations to document the distribution of 1271 territories during the 2004–2006 breeding seasons at three breeding colonies in the Gulf of California, Mexico. Territories were depicted as circular objects and overlaid over one another in ArcINFO®, separated by island and year. Areas with consistent overlap in territory use were identified among years. Territory boundaries and locations were spatially distinct within breeding seasons and at each of the breeding colonies. Males occurring in these areas were partially influenced by island, year, territory size, number of females, aggressive interactions, and distance to nearest neighbor (best fitting model — AIC = 1273.09, ωi= 0.99). However, the best model only accounted for 30% of the variation, indicating that other variables are needed to explain the occurrence of these “hot spots”. Territory site selection, therefore, may be influenced by extrinsic factors under which female choice may be operating resembling a lek-like mating system.
Amul India: A Social Development Enterprise
Authors: Chawla Harish 
Published: April 2008

Amul initiated as an experiment in two villages, collecting 250 kg of milk per day. As the cooperative expanded its branches over the course of its 50-year journey, Amul boasts of more than six million kilograms of milk collection daily. What had initiated as a process of liberation from the Dairy King, brought a revolutionary transformation across the country. This case provides a vivid example of how a cooperative can become the catalyst for social change and rural development. This case takes us through the journey of Amul, from its dawn period when it was attempting to take root, through its progression along the enterprise life stages and the associated challenges. Insights into the quality of leadership and the farmer/management relationships are its defining characteristic. The Amul Model narrowed the gap between the producer and the consumer, connecting the dairy farmer to the consumer through its organic network. The success of this model ignited interest across India, where this model was replicated, in essence leading to the White Revolution. The case provides sufficient insights and learnings to develop a framework to comprehend the basic essence of a prosperous social enterprise — factors that make it successful. It is this learning that this case desires to impart to its readership, enhancing interest in this rather lively subject of social enterprises.
IMPROVED PROJECTION HOPFIELD NETWORK FOR THE QUADRATIC ASSIGNMENT PROBLEM
Authors: TATSUMI KEIJI , TANINO TETSUZO 
Published: April 2008

The continuous-valued Hopfield neural network (CHN) is a popular and powerful metaheuristic method for combinatorial optimization. However, it is difficult to select appropriate penalty parameters for constraints so as to obtain a feasible and desirable solution by CHN. Thus, various improved models have been proposed. Matsuda proposed a CHN named optimal CHN and showed theoretical results on selecting parameters. On the other hand, Smith et al. proposed the projection CHN which projects a solution onto the feasible region and thus needs not select penalty parameters.In this paper, we point out some drawbacks of these two models and propose a new CHN with an efficient projection technique for the quadratic assignment problem, which overcomes these drawbacks. Moreover, we show that the proposed model can always find a feasible solution and that it has the local convergence property. Finally, we verify advantages of the proposed model through some numerical experiments.
First-year students' impressions of pair programming in CS1
Authors: Simon Beth , Hanks Brian 
Published: April 2008

Pair programming, as part of the Agile Development process, has noted benefits in professional software development scenarios. These successes have led to a rise in use of pair programming in educational settings, particularly in Computer Science 1 (CS1). Specifically, McDowell et al. [2006] has shown that students using pair programming in CS1 do better in a CS2 class (with solo programming) than students who don't pair in CS1. This paper seeks to address a similar question, but from a qualitative, student-focused approach. How do students define, experience, and value the pair programming experience? How do they experience and value it compared to solo programming? Does pairing in CS1 impact their confidence in their abilities?
We report on semi-structured interviews with 11 subjects from two institutions where pair programming was used in CS1, and solo programming was used in the CS2. Many of the responses met our expectations; students get stuck less and explore more ideas while pairing, and believe that pair programming helped them in CS1. Other responses were more surprising. Students reported that when solo programming they were more confident and understood their programs better. Many students also said that they started work on their assignments earlier when soloing. Students also continue to use other students as resources even when working "solo."
SEED
Authors: Du Wenliang , Wang Ronghua 
Published: April 2008

The security and assurance of our computing infrastructure has become a national priority. To address this priority, higher education has gradually incorporated the principles of computer and information security into the mainstream undergraduate and graduate computer science curricula. To achieve effective education, learning security principles must be grounded in experience. This calls for effective laboratory exercises (or course projects). Although a number of laboratories have been designed for security education, they only cover a small portion of the fundamental security principles. Moreover, their underlying lab environments are different, making integration of these laboratories infeasible for a semester-long course. Currently, security laboratories that can be widely adopted are still lacking, and they are in great demand in security education.
We have developed a novel laboratory environment (referred to as SEED). The SEED environment consists of Minix, an instructional operating system (OS), and Linux, a production OS; it takes advantage of the simplicity of Minix and the completeness of Linux, and provides a unified platform to support a rich set of laboratories for computer security education. Based on the SEED environment, we have developed a list of laboratories that cover a wide spectrum of security principles. These labs provide opportunities for students to develop essential skills for secure computing practice. We have been using these labs in our courses during the last five years. This article presents our SEED environment, laboratories, and evaluation results.
Streamware
Authors: Gummaraju Jayanth , Coburn Joel , Turner Yoshio , Rosenblum Mendel 
Published: April 2008

Recently, the number of cores on general-purpose processors has been increasing rapidly. Using conventional programming models, it is challenging to effectively exploit these cores for maximal performance. An interesting alternative candidate for programming multiple cores is the stream programming model, which provides a framework for writing programs in a sequential-style while greatly simplifying the task of automatic parallelization. It has been shown that not only traditional media/image applications but also more general-purpose data-intensive applications can be expressed in the stream programming style.
In this paper, we investigate the potential to use the stream programming model to efficiently utilize commodity multicore general-purpose processors (e.g., Intel/AMD). Although several stream languages and stream compilers have recently been developed, they typically target special-purpose stream processors. In contrast, we propose a flexible software system, Streamware, which automatically maps stream programs onto a wide variety of general-purpose multicore processor configurations. We leverage existing compilation framework for stream processors and design a runtime environment which takes as input the output of these stream compilers in the form of machine-independent stream virtual machine code. The runtime environment assigns work to processor cores considering processor/cache configurations and adapts to workload variations. We evaluate this approach for a few general-purpose scientific applications on real hardware and a cycle-level simulator set-up to showcase scaling and contention issues. The results show that the stream programming model is a good choice for efficiently exploiting modern and future multicore CPUs for an important class of applications.
The mapping collector
Authors: Wegiel Michal , Krintz Chandra 
Published: April 2008

Parallel and concurrent garbage collectors are increasingly employed by managed runtime environments (MREs) to maintain scalability, as multi-core architectures and multi-threaded applications become pervasive. Moreover, state-of-the-art MREs commonly implement compaction to eliminate heap fragmentation and enable fast linear object allocation.
Our empirical analysis of object demographics reveals that unreachable objects in the heap tend to form clusters large enough to be effectively managed at the granularity of virtual memory pages. Even though processes can manipulate the mapping of the virtual address space through the standard operating system (OS) interface on most platforms, extant parallel/concurrent compactors do not do so to exploit this clustering behavior and instead achieve compaction by performing, relatively expensive, object moving and pointer adjustment.
We introduce the Mapping Collector (MC), which leverages virtual memory operations to reclaim and consolidate free space without moving objects and updating pointers. MC is a nearly-single-phase compactor that is simpler and more efficient than previously reported compactors that comprise two to four phases. Through effective MRE-OS coordination, MC maintains the simplicity of a non-moving collector while providing efficient parallel and concurrent compaction.
We implement both stop-the-world and concurrent MC in a generational garbage collection framework within the open-source HotSpot Java Virtual Machine. Our experimental evaluation using a multiprocessor indicates that MC significantly increases throughput and scalability as well as reduces pause times, relative to state-of-the-art, parallel and concurrent compactors.
Dispersing proprietary applications as benchmarks through code mutation
Authors: Van Ertvelde Luk , Eeckhout Lieven 
Published: April 2008

Industry vendors hesitate to disseminate proprietary applications to academia and third party vendors. By consequence, the benchmarking process is typically driven by standardized, open-source benchmarks which may be very different from and likely not representative of the real-life applications of interest.
This paper proposes code mutation, a novel technique that mutates a proprietary application to complicate reverse engineering so that it can be distributed as a benchmark. The benchmark mutant then serves as a proxy for the proprietary application. The key idea in the proposed code mutation approach is to preserve the proprietary application's dynamic memory access and/or control flow behavior in the benchmark mutant while mutating the rest of the application code. To this end, we compute program slices for memory access operations and/or control flow operationstrimmed through constant value and branch profiles; and subsequently mutate the instructions not appearing in these slices through binary rewriting.
Our experimental results using SPEC CPU2000 and MiBench benchmarks show that code mutation is a promising technique that mutates up to 90% of the static binary, up to 50% of the dynamically executed instructions, and up to 35% of the at run time exposed inter-operation data dependencies. The performance characteristics of the mutant are very similar to those of the proprietary application across a wide range of microarchitectures and hardware implementations.
Learning from mistakes
Authors: Lu Shan , Park Soyeon , Seo Eunsoo , Zhou Yuanyuan 
Published: April 2008

The reality of multi-core hardware has made concurrent programs pervasive. Unfortunately, writing correct concurrent programs is difficult. Addressing this challenge requires advances in multiple directions, including concurrency bug detection, concurrent program testing, concurrent programming model design, etc. Designing effective techniques in all these directions will significantly benefit from a deep understanding of real world concurrency bug characteristics.
This paper provides the first (to the best of our knowledge) comprehensive real world concurrency bug characteristic study. Specifically, we have carefully examined concurrency bug patterns, manifestation, and fix strategies of 105 randomly selected real world concurrency bugs from 4 representative server and client open-source applications (MySQL, Apache, Mozilla and OpenOffice). Our study reveals several interesting findings and provides useful guidance for concurrency bug detection, testing, and concurrent programming language design.
Some of our findings are as follows: (1) Around one third of the examined non-deadlock concurrency bugs are caused by violation to programmers' order intentions, which may not be easily expressed via synchronization primitives like locks and transactional memories; (2) Around 34% of the examined non-deadlock concurrency bugs involve multiple variables, which are not well addressed by existing bug detection tools; (3) About 92% of the examined concurrency bugs canbe reliably triggered by enforcing certain orders among no more than 4 memory accesses. This indicates that testing concurrent programs can target at exploring possible orders among every small groups of memory accesses, instead of among all memory accesses; (4) About 73% of the examinednon-deadlock concurrency bugs were not fixed by simply adding or changing locks, and many of the fixes were not correct at the first try, indicating the difficulty of reasoning concurrent execution by programmers.
The design and implementation of microdrivers
Authors: Ganapathy Vinod , Renzelmann Matthew J. , Balakrishnan Arini , Swift Michael M. , Jha Somesh 
Published: April 2008

Device drivers commonly execute in the kernel to achieve high performance and easy access to kernel services. However, this comes at the price of decreased reliability and increased programming difficulty. Driver programmers are unable to use user-mode development tools and must instead use cumbersome kernel tools. Faults in kernel drivers can cause the entire operating system to crash. User-mode drivers have long been seen as a solution to this problem, but suffer from either poor performance or new interfaces that require a rewrite of existing drivers.
This paper introduces the Microdrivers architecture that achieves high performance and compatibility by leaving critical path code in the kernel and moving the rest of the driver code to a user-mode process. This allows data-handling operations critical to I/O performance to run at full speed, while management operations such as initialization and configuration run at reduced speed in user-level. To achieve compatibility, we present DriverSlicer, a tool that splits existing kernel drivers into a kernel-level component and a user-level component using a small number of programmer annotations. Experiments show that as much as 65% of driver code can be removed from the kernel without affecting common-case performance, and that only 1-6 percent of the code requires annotations.
Blood Vessel Maturation and Response to Vascular-Disrupting Therapy in Single Vascular Endothelial Growth Factor-A Isoform–Producing Tumors
Authors: Tozer Gillian M. , Akerman Simon , Cross Neil A. , Barber Paul R. , Björndahl Meit A. , Greco Olga , Harris Sheila , Hill Sally A. , Honess Davina J. , Ireson Christopher R. , Pettyjohn Katie L. , Prise Vivien E. , Reyes-Aldasoro Constantino C. , Ruhrberg Christiana , Shima David T. , Kanthou Chryso 
Published: April 2008

Abstract
Tubulin-binding vascular-disrupting agents (VDA) are currently in clinical trials for cancer therapy but the factors that influence tumor susceptibility to these agents are poorly understood. We evaluated the consequences of modifying tumor vascular morphology and function on vascular and therapeutic response to combretastatin-A4 3-O-phosphate (CA-4-P), which was chosen as a model VDA. Mouse fibrosarcoma cell lines that are capable of expressing all vascular endothelial growth factor (VEGF) isoforms (control) or only single isoforms of VEGF (VEGF120, VEGF164, or VEGF188) were developed under endogenous VEGF promoter control. Once tumors were established, VEGF isoform expression did not affect growth or blood flow rate. However, VEGF188 was uniquely associated with tumor vascular maturity, resistance to hemorrhage, and resistance to CA-4-P. Pericyte staining was much greater in VEGF188 and control tumors than in VEGF120 and VEGF164 tumors. Vascular volume was highest in VEGF120 and control tumors (CD31 staining) but total vascular length was highest in VEGF188 tumors, reflecting very narrow vessels forming complex vascular networks. I.v. administered 40 kDa FITC-dextran leaked slowly from the vasculature of VEGF188 tumors compared with VEGF120 tumors. Intravital microscopy measurements of vascular length and RBC velocity showed that CA-4-P produced significantly more vascular damage in VEGF120 and VEGF164 tumors than in VEGF188 and control tumors. Importantly, this translated into a similar differential in therapeutic response, as determined by tumor growth delay. Results imply differences in signaling pathways between VEGF isoforms and suggest that VEGF isoforms might be useful in vascular-disrupting cancer therapy to predict tumor susceptibility to VDAs. [Cancer Res 2008;68(7):2301–11]
Risk Stratification in Cancer Predisposition Syndromes: Lessons Learned from Novel Molecular Developments in Li-Fraumeni Syndrome
Authors: Tabori Uri , Malkin David 
Published: April 2008

Abstract
Germ-line mutations in specific genes predispose family members to cancer. Prediction of the exact tumor type and timing of cancer initiation is fundamental to the development of management strategies for these individuals. Recent advances in our understanding of the general processes that control cancer initiation may enable us to tailor more precise risk stratification. This, in turn, will lead to more effective early detection strategies, which would result in more favorable clinical outcomes. In this review, we highlight the steps and methods used to reach this futuristic model. [Cancer Res 2008;68(7):2053–7]
The Cyclin-Dependent Kinase Inhibitor Flavopiridol Potentiates the Effects of Topoisomerase I Poisons by Suppressing Rad51 Expression in a p53-Dependent Manner
Authors: Ambrosini Grazia , Seelman Sharon L. , Qin Li-Xuan , Schwartz Gary K. 
Published: April 2008

AbstractThe results of a phase I clinical trial of the topoisomerase I (Topo I) poison CPT-11 followed by the cyclin-dependent kinase inhibitor flavopiridol in patients with advanced solid tumors indicate that patients whose tumors were wild-type, but not mutant, for p53 obtained the most clinical benefit from this combination therapy. We elected to elucidate the mechanistic basis for this effect in isogenic-paired HCT116 colon cancer cells that were either wild-type (+/+) or null (−/−) for p53. With the combination therapy of SN-38 (the active metabolite of CPT-11) followed by flavopiridol, the induction of apoptosis was 5-fold greater in the p53+/+ cells compared with the p53−/− cells. This sequential treatment induced phosphorylation of p53 at Ser15, which interacted with Rad51, a DNA repair protein involved in homologous recombination. Rad51 bound to p53-Ser15 within the first 5 hours of combination therapy, and then was transcriptionally suppressed at 24 hours by flavopiridol only in p53+/+ cells. Microarray analysis also revealed suppression of Rad51 in a p53-dependent manner. Depletion of Rad51 by small interfering RNA (siRNA) sensitized both p53+/+ and p53−/− cells to SN-38–induced apoptosis with increase of γH2AX, a marker of DNA damage. Conversely, overexpression of Rad51 rescued p53+/+ cells from SN→F–induced apoptosis. Because flavopiridol inhibits Cdk9, we found that inhibition of Cdk9 by DRB or by siRNA could recapitulate the flavopiridol effects, with suppression of Rad51 and induction of apoptosis only in p53+/+ cells. In conclusion, after DNA damage by Topo I poisons, flavopiridol targets homologous recombination through a p53-dependent down-regulation of Rad51, resulting in enhancement of apoptosis. [Cancer Res 2008;68(7):2312–20]