bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification impossible?
Authors: Römer Ute
Published: April 2008

Evaluation is a pervasive element in spoken and written language but its identification poses serious problems to linguistic researchers, especially when they are dealing with larger amounts of text which require the application of computer-assisted analytic techniques. This article explores ways of identifying items of evaluative meaning in a three million word corpus of linguistic book reviews, a text type that is particularly rich in expressions of positive and negative evaluation. It discusses whether it is at all possible to capture evaluation in a corpus in a systematic way and which analytic strategies may be most promising in the search for a larger set of meaningful patterns. The paper ends with a discussion of some unresolved issues in the area of evaluation research and sketches tasks for future activities in the field.
Complex predicates and bipartite stems in Skou
Authors: Donohue Mark
Published: April 2008

I examine a range of complex predicates, searching for ones that might be called ‘bipartite stems’ in Skou, a language of New Guinea. First I draw a tentative distinction between serial verb constructions and N+V predicates on the one hand, and ‘true’ bipartite stems on the other, while pointing out some complications involved in making this division. Following this I examine the range of stems that can possibly be called ‘bipartite stems’, and those that certainly can be, concluding that the label is not a useful one in describing Skou, which shows more complexities than a simple ‘±bipartite’ dichotomy can capture. A survey of ‘bipartite’ phenomena in related and geographically close languages follows, with the conclusion that prosodic factors at least as much as morphological ones, and the possibility of an infixal analysis, rob the label ‘bipartite’ of much of its useful content when applied outside the domain for which it was originally devised.
Evidentials and clause modality in Wanano
Authors: Stenzel Kristine
Published: April 2008

This paper investigates evidentiality as a category of clause modality in Wanano (Eastern Tukanoan). I discuss four major categories of modality by which statements, questions, and ‘oriented’ utterances are grammatically and obligatorily marked and explore areas of semantic overlap. The major focus is the complex and typologically interesting Wanano evidential system, and I describe the core and extended semantics of each of the five categories — HEARSAY, VISUAL, NON-VISUAL, INFERENCE, and ASSERTION. This description provides input to the theoretical discussion of the relationship between evidentials and epistemic values. I conclude that in Wanano, not only statements coded by evidentials but also statements referring to irrealis situations and interrogatives display sensitivity to scalar values of speaker commitment.
Tuberculosis of the parotid gland: computed tomographic findings
Authors: Wei Y. , Xiao J. , Pui M. H. , Gong Q.
Published: April 2008

Background: Tuberculosis (TB) of the parotid gland is rare, even in endemic regions. Approximately 100 cases have been reported in the English literature. The computed tomographic (CT) features, however, have seldom been studied.

Purpose: To determine the diagnostic CT features of tuberculosis of the parotid gland.

Material and Methods: CT studies of four histologically proven cases of tuberculosis of the parotid gland were retrospectively reviewed.

Results: A total of 15 enlarged lymph nodes were found in the superficial lobes of the parotid glands. The nodes were arranged linearly within the gland. Enhancement patterns included homogeneous enhancement (9/15, 60%), homogeneous enhancement with eccentric microcysts (3/15, 20%), and thick-walled rim enhancement with central lucency (3/15, 20%). Thickened adjacent fascial plane and platysma were seen in two patients. Ipsilateral cervical lymphadenopathy was seen in all patients.

Conclusion: In patients presenting with unilateral parotid nodules, TB should be considered when linearly arranged enhancing nodules are demonstrated in the superficial lobes of the glands on CT scan.
Semaphorin controls epidermal morphogenesis by stimulating mRNA translation via eIF2α in Caenorhabditis elegans
Authors: Nukazuka Akira , Fujisawa Hajime , Inada Toshifumi , Oda Yoichi , Takagi Shin
Published: April 2008

Conserved semaphorin–plexin signaling systems govern various aspects of animal development, including axonal guidance in vertebrates and epidermal morphogenesis in Caenorhabditis elegans. Here we provide in vivo evidence that stimulation of mRNA translation via eukaryotic initiation factor 2α (eIF2α) is an essential downstream event of semaphorin signaling in C. elegans. In semaphorin/plexin mutants, a marked elevation in the phosphorylation of eIF2α is observed, which causes translation repression and is causally related to the morphological epidermal phenotype in the mutants. Conversely, removal of constraints on translation by genetically reducing the eIF2α phosphorylation largely bypasses requirement for the semaphorin signal in epidermal morphogenesis. We also identify an actin-depolymerizing factor/cofilin, whose expression in the mutants is predominantly repressed, as a major translational target of semaphorin signaling. Thus, our results reveal a physiological significance for translation of mRNAs for cytoskeletal regulators, linking environmental cues to cytoskeletal rearrangement during cellular morphogenesis in vivo.
Fine-tuning of hematopoietic stem cell homeostasis: novel role for ubiquitin ligase
Authors: Yokomizo Tomomasa , Dzierzak Elaine
Published: April 2008

Homeostasis of hematopoietic stem cells (HSCs) is a tightly regulated process, controlled by intrinsic and extrinsic signals. Although a variety of molecules involved in HSC maintenance and self-renewal are known, it remains unclear how robust HSC homeostasis is achieved. In this issue of Genes & Development, Rathinam and colleagues (992–997) report a new player in HSC homeostasis, c-Cbl ubiq-uitin ligase. They show that this E3 ubiquitin ligase acts as a negative regulator of cytokine signaling.
Heterogeneity influences spatial patterns and demographics in forest stands
Authors: Getzin Stephan , Wiegand Thorsten , Wiegand Kerstin , He Fangliang
Published: April 2008

The spatial pattern of tree species retains signatures of factors and processes such as dispersal, available resource patches for establishment, competition and demographics. Comparison of the spatial pattern of different size classes can thus help to reveal the importance and characteristics of the underlying processes. However, tree dynamics may be masked by large‐scale heterogeneous site conditions, e.g. when the restricting size of regeneration sites superimposes emergent patterns.

Here we ask how environmental heterogeneity may influence the spatial dynamics of plant communities. We compared the spatial patterns and demographics of western hemlock in a homogeneous and a heterogeneous site of old‐growth Douglas‐fir forests on Vancouver Island using recent techniques of point pattern analysis. We used homogeneous and inhomogeneous K‐ and pair‐correlation functions, and case‐control studies to quantify the change in spatial distribution for different size classes of western hemlock.

Our comparative analyses show that biological processes interacted with spatial heterogeneity, leading to qualitatively different population dynamics at the two sites. Population structure, survival and size structure of western hemlock were different in the heterogeneous stand in such a way that, compared to the homogeneous stand, seedlings were more clustered, seedling densities higher, seedling mortality lower, adult growth faster and adult mortality higher. Under homogeneous site conditions, seedling survival was mainly abiotically determined by random arrival in small gaps with limiting light. At the heterogeneous site, seedling densities and initial survival were much higher, leading to strong density‐dependent mortality and selection for faster growing individuals in larger size classes. We hypothesise that the dynamics of the heterogeneous stand were faster due to asymmetric competition with disproportionate benefit to taller plants.

Synthesis. Our study supports the hypothesis that successional dynamics are intensified in heterogeneous forest stands with strong spatial structures and outlines the importance of spatial heterogeneity as a determinant of plant population dynamics and pattern formation.
Multiple paternity or multiple queens: two routes to greater intracolonial genetic diversity in the eusocial Hymenoptera
Authors: HUGHES W. O. H. , RATNIEKS F. L. W. , OLDROYD B. P.
Published: April 2008

Understanding the evolution of multiple mating by females (polyandry) is an important question in behavioural ecology. Most leading explanations for polyandry by social insect queens are based upon a postulated fitness benefit from increased intracolonial genetic diversity, which also arises when colonies are headed by multiple queens (polygyny). An indirect test of the genetic diversity hypotheses is therefore provided by the relationship between polyandry and polygyny across species, which should be negative if the genetic diversity hypotheses are correct. Here, we conduct a powerful comparative investigation of the relationship between polyandry and polygyny for 241 species of eusocial Hymenoptera (ants, bees and wasps). We find a clear and significant negative relationship between polyandry and polygyny after controlling for phylogeny. These results strongly suggest that fitness benefits resulting from increased intracolonial genetic diversity have played an important role in the evolution of polyandry, and possibly polygyny, in social insects.
Measurement of development of cognitive and attention functions in children using continuous performance test
Authors: Kanaka Noriko , Matsuda Tetsuya , Tomimoto Yasushi , Noda Yuji , Matsushima Eisuke , Matsuura Masato , Kojima Takuya
Published: April 2008

Aim:  The development of attention function in children is still not sufficiently clear. Although it is difficult to objectively assess attention function, continuous performance tests (CPT) can be used to objectively assess cognitive function along with attention. The development of cognitive and attention functions was examined in children using a CPT.

Methods:  A total of 541 healthy girls aged 5–12 years participated. Ten parameters were calculated: numbers of cancellations for either target stimuli (T‐cancel) or non‐target stimuli (N‐cancel), numbers of omission errors (Omission) and commission errors (Commission), hit rate (Hit), false alarm rate (False), mean reaction time for correct response (RT), coefficient of variance for mean reaction time (CVRT), sensitivity index (d′), and lnβ.

Results:  The parameters were divided into three types based on pattern of change. T‐cancel, False, and Commission, which are related to inhibition of response, N‐cancel, Hit, and Omission, which are related to inattention to stimuli, and CVRT, which is related to stability of processing time, exhibited significant change until 5 or 6 years of age. d′, which is related to ability to discriminate between target or non‐target, exhibited significant change until 8 years of age. RT, which is related to processing time, exhibited significant change until 11 years of age. lnβ exhibited no significant differences among age groups.

Conclusions:  These findings indicate that inhibition function, inattention to stimuli, and stability of processing time develop first. Discrimination ability subsequently increases based on these developments, and finally processing time is reduced.
Factor structure of the Japanese Interpersonal Competence Scale
Authors: Matsudaira Tomomi , Fukuhara Taihei , Kitamura Toshinori
Published: April 2008

Aim:  Assessing social competence is important for clinical and preventive interventions of depression. The aim of the present paper was to examine the factor structure of the Japanese Interpersonal Competence Scale (JICS).

Methods:  Exploratory and confirmatory factor analysis was performed on the survey responses of 730 participants. Simultaneous multigroup analyses were conducted to confirm factor stability across psychological health status and sex differences.

Results:  Two factors, which represent Perceptive Ability and Self‐Restraint, were confirmed to show a moderate correlation. Perceptive Ability involves a more cognitive aspect of social competence, while Self‐Restraint involves a more behavioral aspect, both of which are considered to reflect the emotion‐based relating style specific to the Japanese people: indulgent dependence (amae) and harmony (wa). In addition, Self‐Restraint may be linked to social functioning. Both constructs may confound a respondent's perceived confidence.

Conclusion:  Despite its shortcomings, the JICS is a unique measure of social competence in the Japanese cultural context.
Poor performance in Clock‐Drawing Test associated with visual memory deficit and reduced bilateral hippocampal and left temporoparietal regional blood flows in Alzheimer's disease patients
Authors: Takahashi Megumi , Sato Aiko , Nakajima Keisuke , Inoue Aya , Oishi Satoru , Ishii Takayoshi , Miyaoka Hitoshi
Published: April 2008

Aim:  To investigate the associations of Clock‐Drawing Test (CDT) score with neuropsychological test scores and regional cerebral blood flow.

Method:  Twenty‐five patients (normal aging, n = 2; mild cognitive impairment, n = 7; Alzheimer's disease [AD], n = 16) participated in this study. Their average age was 74.8 years.

Results:  CDT score correlated well with the neuropsychological test scores of Mini‐Mental State Examination, Clinical Dementia Rating, immediate visual memory, delayed visual memory, and IQ evaluated by Koh's block design. CDT score also had a statistically significant correlation with the regional blood flow in the left hippocampal region as evaluated on 3‐D stereotaxic region‐of‐interest template analysisapplied to single‐photon emission computed tomography images. Using a cut‐off point of 8/9 in the CDT, the high‐CDT group had significantly higher delayed visual memory and IQ scores than the low‐CDT group. Moreover, the high‐CDT group had significantly higher regional blood flows in the left parietal, left angular and bilateral hippocampal regions than the low‐CDT group.

Conclusion:  CDT score correlates well with regional cerebral blood flow that is decreased in the early stage of AD.
Alterations in prefrontal cortical activity in the course of treatment for late‐life depression as assessed on near‐infrared spectroscopy
Authors: Onishi Yasunori , Kikuchi Senichiro , Watanabe Eiju , Kato Satoshi
Published: April 2008

Aim:  To evaluate the severity of depression by measuring alterations in prefrontal cortical activity associated with mood disorders, as assessed on near‐infrared spectroscopy.

Methods:  Ten of 27 subjects hospitalized for late‐life depression from May 2006 to June 2007, were examined. In these 10 subjects changes in hemoglobin concentration were measured on near‐infrared spectroscopy during two types of the rock, paper, scissors game as the cognitive tasks affecting prefrontal cortical activity on 2 days, including 1 day on which depressive symptoms had slightly improved due to treatment, and then on another day >4 weeks later. Severity of depression and cognitive impairment were also simultaneously assessed.

Results:  The change in oxygenated hemoglobin concentration during a difficult task (intentional loss task) was significantly larger than that during an easy task (try to win task) on the left side (left, P = 0.010; right, P = 0.059). On the left side there was a significant negative correlation between the ratio of oxygenated hemoglobin measurements on the second day to those on the first day, and the severity of depression on the second day (left, P = 0.012; right, P = 0.090). Thus, the more left prefrontal cortical activity tended to increase, the fewer depressive symptoms tended to be present on the second day of testing.

Conclusions:  Measuring of alterations in prefrontal cortical activity associated with mood disorders, as assessed on near‐infrared spectroscopy, is feasible in subjects with depression.
Confabulation behavior and false memories in Korsakoff's syndrome: Role of source memory and executive functioning
Authors: Kessels Roy P. C. , Kortrijk Hans E. , Wester Arie J. , Nys Gudrun M. S.
Published: April 2008

Aims:  Confabulation behavior is common in patients with Korsakoff's syndrome. A distinction can be made between spontaneous and provoked confabulations, which may have different underlying cognitive mechanisms. Provoked confabulations may be related to intrusions on memory tests, whereas spontaneous confabulations may be due to executive dysfunction or a source memory deficit.

Methods:  In 19 chronic Korsakoff patients, spontaneous confabulations were quantified by third‐party rating (Likert scale). Provoked confabulations were assessed using the Dalla Barba Confabulation Battery. Furthermore, assessment of executive function was performed using an extensive neuropsychological battery. False memories (i.e. intrusions) and source memory were measured using twoparallelversions of a word‐list learning paradigm (a modification of the Rey Auditory Verbal Learning Test).

Results:  There were deficits in source memory, in which patients incorrectly assigned previously learned words to an incorrect word list. Also, Korsakoff patients had extensive executive deficits, but no relationship between the severity of these deficits and the severity of confabulation or intrusions on a memory task was found.

Conclusion:  The present findings provide evidence for a dissociation between spontaneous confabulation, provoked confabulation and false memories.
The ongoing variability in blood transfusion practices in cardiac surgery
Authors: Snyder‐Ramos Stephanie A. , Möhnle Patrick , Weng Yi‐Shin , Böttiger Bernd W. , Kulier Alexander , Levin Jack , Mangano Dennis T. ,   Investigators of the Multicenter Study of Perioperative Ischemia,   MCSPI Research Group
Published: April 2008

BACKGROUND: Although blood utilization has been under considerable scrutiny for the past two decades, particularly for surgery, studies comparing perioperative blood transfusion practices between countries are rare, and the evolution of international standards remains unknown. Therefore, the objective of this evaluation was to compare the perioperative transfusion of blood components in cardiac surgery in multiple centers in different countries.

STUDY DESIGN AND METHODS: Transfusion practice was investigated prospectively in 70 centers among 16 countries. A total of 5065 randomly selected cardiac surgery patients of the Multicenter Study of Perioperative Ischemia Epidemiology II (EPI II) Study were evaluated. Utilization of red blood cells (RBCs), fresh‐frozen plasma (FFP), and platelets (PLTs) was assessed daily, before, during, and after surgery until hospital discharge.

RESULTS: Intraoperative RBC transfusion varied from 9 to 100 percent among the 16 countries, and 25 to 87 percent postoperatively (percentage of transfused patients). Similarly, frequency of transfusion of FFP varied from 0 to 98 percent intraoperatively and 3 to 95 percent postoperatively, and PLT transfusion from 0 to 51 and 0 to 39 percent, respectively. Moreover, there were not only marked differences in transfusion rates between centers in different countries but also in interinstitutional comparison of multiple centers within countries.

CONCLUSION: In cardiac surgical patients, marked variability in transfusion practice exists between centers in various countries and suggests differences in perioperative practice patterns as well as possible inappropriate use. International standardization of perioperative practice patterns as well as transfusion regimes appears necessary.
Opportunities and Challenges of Sexual Health Services Among Young People: A Study in Nepal
Authors: Regmi Krishna
Published: April 2008

Introduction

It has been well documented that young people are more likely to engage in high-risk sexual activity. Appropriate understanding of safe sex, sexual practices, and related behaviors must recognize the importance of socioeconomic and cultural factors in prevention efforts related to HIV and other sexual transmitted infections (STIs).

Aim

To examine and summarize the opportunities and challenges of sexual health services among young people in Nepal.

Main Outcome Measures

Review of literature—assessing knowledge, attitudes, and understanding of sex, sexual health, and related sexual risk behaviors, among young people (15–24), in line with the current sociocultural and health service practices.

Methods

Medline, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Science, Cochrane database, and Google were searched. Similarly, documents published at the WHO, United Nations Population Fund, United Nations Development Program, and at national/local level—Ministry of Health, National Center for AIDS, and STD Control were also assessed to access the relevant reports and articles. Published and gray articles were also reviewed.

Results

This study contends growing expansion of communication and transportation networks, urbanization, and urban in-migration is creating a different sociocultural environment, which is conducive to more social interactions between young girls and boys in Nepal. Rising age at marriage opens a window of opportunity for premarital and unsafe sexual activity among young people and this creates risks of unwanted pregnancy, STIs/HIV and AIDS. Socioeconomic, demographic, and cultural factors have been identified as encouraging factors for risk-taking behaviors among young people.

Conclusions

Understanding safer sex and responsible sexual/reproductive behavior is important. Effective and appropriate interventions on sexual and reproductive health education directed at young people and the whole family, including fathers, could have significant effect on reducing risk and related risk practices in the context of Nepal.
Impact of Premature Ejaculation: The Psychological, Quality of Life, and Sexual Relationship Consequences
Authors: Rosen Raymond C. , Althof Stanley
Published: April 2008

Introduction

Premature ejaculation (PE) has been associated with a range of negative psychological effects, including anxiety, depression, and distress in men and their female partners.

Aim

To review evidence of the psychosocial concomitants of premature ejaculation in recent observational studies, and to consider the psychosocial and quality of life outcomes associated with PE, including effects on the partner relationship.

Main Outcome Measure

Psychosocial and quality of life consequences related to premature ejaculation.

Methods

A literature search was performed to retrieve publications relating to management or treatment of PE or male sexual dysfunction. Publications were included if they reported the impact of PE on the man, his partner or relationship, or the impact of male sexual dysfunction and included PE in the analysis.

Results

Eleven observational studies were selected. All these studies found evidence for an association between PE and adverse psychosocial and quality of life consequences, including detrimental effects on the partner relationship. Comparative analyses were restricted by major differences across the studies.

Conclusions

PE significantly negatively impacts men and their partners and may prevent single men forming new partner relationships. Men are reluctant to seek treatment from their physicians, although they may be more encouraged to do so through their partner's support and the availability of effective treatments. There is a need for validated diagnostic screening criteria and validated, reliable, brief patient-reported outcome measures that can be used to assess men with PE and their partners. These factors would allow further studies with more complete and accurate assessment of the impact of PE.
Medusan morphospace: phylogenetic constraints, biomechanical solutions, and ecological consequences
Authors: Costello John H. , Colin Sean P. , Dabiri John O.
Published: April 2008

Abstract. Medusae were the earliest animals to evolve muscle‐powered swimming in the seas. Although medusae have achieved diverse and prominent ecological roles throughout the world's oceans, we argue that the primitive organization of cnidarian muscle tissue limits force production and, hence, the mechanical alternatives for swimming bell function. We use a recently developed model comparing the potential force production with the hydrodynamic requirements of jet propulsion, and conclude that jet production is possible only at relatively small bell diameters. In contrast, production of a more complex wake via what we term rowing propulsion permits much larger sizes but requires a different suite of morphological features. Analysis of morphometric data from all medusan taxa independently confirms size‐dependent patterns of bell forms that correspond with model predictions. Further, morphospace analysis indicates that various lineages within the Medusozoa have proceeded along either of two evolutionary trajectories. The first alternative involved restriction of jet‐propelled medusan bell diameters to small dimensions. These medusae may be either solitary individuals (characteristic of Anthomedusae and Trachymedusae) or aggregates of small individual medusan units into larger colonial forms (characteristic of the nectophores of many members of the Siphonophorae). The second trajectory involved use of rowing propulsion (characteristic of Scyphozoa and some hydromedusan lineages such as the Leptomedusae and Narcomedusae) that allows much larger bell sizes. Convergence on either of the differing propulsive alternatives within the Medusozoa has emerged via parallel evolution among different medusan lineages. The distinctions between propulsive modes have important ecological ramifications because swimming and foraging are interdependent activities for medusae. Rowing swimmers are characteristically cruising predators that select different prey types from those selected by jet‐propelled medusae, which are predominantly ambush predators. These relationships indicate that the different biomechanical solutions to constraints on bell function have entailed ecological consequences that are evident in the prey selection patterns and trophic impacts of contemporary medusan lineages.
Size‐dependent sex allocation and sexual selection in Aplysia kurodai, a hermaphrodite with nonreciprocal mating
Authors: Yusa Yoichi
Published: April 2008

Abstract. For simultaneous hermaphrodites, a male‐to‐female shift in sex allocation with growth, and weak sexual selection on the male function, is predicted by many theories, although empirical data for both predictions are insufficient for internally fertilizing hermaphrodites with nonreciprocal mating. To address these issues, I studied mating and egg‐laying behavior of the sea hare, Aplysia kurodai (Gastropoda: Opisthobranchia) in the laboratory. Both frequency and duration of egg laying increased with body weight, indicating that fecundity increased with weight. On the other hand, frequency and duration of mating as males did not increase with body weight, suggesting that sperm usage was independent of weight. Therefore, sex allocation shifted from male to female functions with growth. The lack of a relationship between body weight and mating activities as males also suggests that there was no “female” choice for large partners. However, the frequency of mating as females increased with body weight, suggesting “male” choice for large partners. This “male” choice is further supported by the presence of size‐assortative mating and a longer duration of mating when the female partner was large. In addition, the variance in mating frequency as females was larger than that as males. As a whole, the mating behavior in A. kurodai can be summarized as choosy as males and unchoosy as females, the opposite of the patterns known in most gonochoric and hermaphroditic animals.
Sexual dimorphism in the compound eye of the moth Operophtera brumata (Lepidoptera, Geometridae)
Authors: Meyer‐Rochow Victor Benno , Lau Ting Fan (Stanley)
Published: April 2008

Abstract. Brachyptery in female moths is a common phenomenon. This article examines the eyes of the moth Operophtera brumata, in which only the males have wings. Both sexes possess eyes of the superposition type, have facets with corneal nipples, and exhibit eyeglow, but the eye of the male has 2174 facets, measures 725 μm in diameter, and has a clear zone of 112‐μm width. That of the female has 1352 facets, measures 557 μm across, and has a 77‐μm‐wide clear zone. There were no significant differences in rhabdom diameters (10 μm) and tracheal sheath development, but male rhabdoms were significantly longer (85 vs. 65 μm). Dark/light adaptational changes manifested themselves in the positions of the distal screening pigment granules: between the cones during darkness and into the clear zone during light adaptation. The combination of a larger radius of curvature, wider clear zone, and longer rhabdoms gives the males a sensitivity at least twice that of the female. The narrower interommatidial angles of the male (2.8° vs. 3.2°) together with the well‐developed tracheal rhabdom sheaths, furthermore, provide the eyes of the males with better resolution. Finally, eye‐glow intensity in males diminishes considerably faster in light than it does in females. The differences between males and females appear to reflect their different roles: males begin to search after sunset in and around stands of trees for the pheromone‐emitting females, which sit on the trunk of the tree under which they had emerged from their pupal case. Flying males encounter rapid light intensity changes and have to evade obstacles and enemies. The females are considerably more sedentary, but once mated, still seek suitable oviposition sites long after the males have ceased searching for them. During this activity, the females also need visual sensitivity and acuity, but less than the actively flying males.
Sperm morphology in the black coral Cirrhipathes sp. (Anthozoa, Antipatharia)
Authors: Gaino Elda , Bo Marzia , Boyer Massimo , Scoccia Francesca
Published: April 2008

Abstract. Male polyps of the antipatharian Cirrhipathes sp., collected along the coral reef of Siladen Island (Sulawesi, Indonesia), were studied in order to gain an insight into the reproductive biology. Spermatocysts (maximum size 120 μm) are located within the primary gametogenic mesenteries and are separated by mesenteric cell cytoplasmic extensions. Sperm, maturing along radial rows, have a fairly round shape and contain a series of electron‐dense vesicles in the apical nuclear region. A single mitochondrion flanks the nucleus. A peculiar cup‐like electron‐dense body, edged with regularly spaced electron‐dense granules, is interposed between the nucleus and the tail, and delimits a central region that includes two centrioles. Cross‐sections of the cup‐like body reveal that the distal centriole has a pericentriolar system, consisting of nine arms arranged in a radial pattern. Each arm branches into three processes that are connected to the electron‐dense granules. Indirect evidence of spawning is derived from the accumulation of sperm in the gastric cavity. This process takes place through the lysis of the cells bordering the mesenteries. Intact cells of this bordering layer appear to be involved in the phagocytosis of non‐expelled gametes.
Detection ofLeishmania infantumby real‐time PCR in a canine blood bank
Authors: Tabar M. D. , Roura X. , Francino O. , Altet L. , Ruizde Gopegui R.
Published: April 2008

Objectives:Risk for transmission ofLeishmania infantumfrom blood products has been largely demonstrated in human and veterinary literature. Appropriate screening of canine blood donors is important especially in an endemic area such as Barcelona (Spain). The purpose of this study was to evaluate the presence ofL infantumDNA parasites by real‐time quantitative PCR in our canine blood bank.

Methods:Samples from blood products obtained from 92 canine blood donors were assayed forL infantumby means of real‐time PCR amplification and quantification.

Results:The prevalence of quantitative PCR‐positive blood samples among healthy seronegative blood donors was 19·6 per cent.

ClinicalSignificance:The results of this study show thatL infantuminfection is common in canine blood donors and their blood products in an endemic area, despite a negative commercial serological screening for infectious diseases. Therefore, screening by PCR should be included in an integrated approach to evaluateL infantuminfection among potential blood donors.
A retrospective study of the clinical presentation of 140 dogs and 39 cats with bacteraemia
Authors: Greiner M. , Wolf G. , Hartmann K.
Published: April 2008

Objectives: To evaluate retrospective data from 140 dogs and 39 cats with positive blood cultures that were presented to the Clinic for Small Animal Medicine in Munich from 1995 to 2004.

Methods: The identity of bacteria isolated from blood cultures of dogs and cats with bacteraemia was determined, and clinical and laboratory findings and outcome of animals with Gram‐negative versus Gram‐positive bacteraemia were compared.

Results: Sepsis was diagnosed in 81·7 per cent of dogs and 59·5 per cent of cats with bacteraemia. Escherichia coli was isolated in one third of the animals. Dogs with bacteraemia more often showed monocytosis and increased alkaline phosphatase activity, while in cats, hyperglycaemia was found more commonly. Dogs with Gram‐negative bacteraemia had hypoalbuminaemia significantly more often than dogs with Gram‐positive bacteraemia, while among the remaining parameters, there were no statistically significant differences.

Clinical Significance: Not all dogs and cats with a positive blood culture met the criteria for sepsis. Bacteraemia caused by Gram‐positive versus Gram‐negative bacteria cannot be distinguished based on clinical or laboratory parameters, and bacterial culture and susceptibility testing have to be performed for the right choice of antibiotic treatment.
A Formal Approach to Integrating Computer-Aided Process Planning and Shop Floor Control
Authors: Cho H. , Derebail A. , Hale T. , Wysk R. A.
Published: April 2008

A formal approach for integrating Computer-Aided Design (CAD), Computer-Aided Process Planning (CAPP), and shop floor control for rotational components is presented in this paper. It is assumed that this approach will be implemented within the framework of a three level hierarchical CIM architecture that consists of the following levels in the hierarchy: shop floor, workstation and equipment (Joshi et al., 1991). Our approach to CAPP consists of machining feature identification, definition, classification, representation, and reasoning, provided through a CAD model of a product. Geometric entities are identified from a Drawing Exchange Format (DXF) file. The identified entities form the basis for the construction of primitive manufacturing features. The primitive features are assembled together based upon the precedence among features, into a graph, called a feature graph. However, the primitive features may or may not be manufacturable in terms of depth of cut, tool geometry, surface finish, and material handling required. Hence it is necessary to convert the feature graph into a manufacturing task graph, which consists of specifications of alternative functional tasks that are manufacturable. The task graph may be converted into a hierarchical set of process plans, based on the planning criteria at each level in the control hierachy, to reflect the processing requirements at each level. The shop planning function decomposes the task graph into a set of workstation level plans. Each workstation level plan is aggregated into a set of equipment level process plans by the workstation planning function. The equipment level plan is converted into a unique task sequence by the equipment planning function. This sequence is then executed according to specifications by the equipment level execution function. Provision of alternative routes in process plans provides for flexible means of on-line planning and control.
On-Line Tool Breakage Detection in Turning: A Multi-Sensor Method
Authors: Colgan J. , Chin H. , Danai K. , Hayashi S. R.
Published: April 2008

A multi-sensor tool breakage detection system is introduced that characterizes the state of measurements during normal (no-fault) condition and at tool breakage by the two columns of a multi-valued influence matrix (MVIM). In this system the measurements are monitored on-line and flagged upon the detection of abnormalities. Tool breakage detection is performed by matching this vector of flagged measurements against the two columns of MVIM, which are estimated during a training session so as to minimize the error in detection. The detection system is implemented in turning. Experimental results indicate that this system provides excellent detection when the full range of tool breakage effect on the measurements is included in training, and that its performance is less dependent upon the training set than a multilayer neural net.
Convolution Analysis of Milling Force Pulsation
Authors: Wang J.-J. Junz , Liang S. Y. , Book W. J.
Published: April 2008

This paper presents the establishment of a closed form expression for the dynamic forces as explicit functions of cutting parameters and tool/workpiece geometry in milling processes. Based on the existing local cutting force model, the generation of total cutting forces is formulated as the angular domain convolution of three cutting process component functions, namely the elementary cutting function, the chip width density function, and the tooth sequence function. The elemental cutting force function is related to the chip formation process in an elemental cutting area and it is characterized by the chip thickness variation, and radial cutting configuration. The chip width density function defines the chip width per unit cutter rotation along a cutter flute within the range of axial depth of cut. The tooth sequence function represents the spacing between flutes as well as their cutting sequence as the cutter rotates. The analysis of cutting forces is extended into the Fourier domain by taking the frequency multiplication of the transforms of the three component functions. Fourier series coefficients of the cutting forces are shown to be explicit algebraic functions of various tool parameters and cutting conditions. Numerical simulation results are presented in the frequency domain to illustrate the effects of various process parameters. A series of end milling experiments are performed and their results discussed to validate the analytical model.
Optimal Budgeting of Quasistatic Machine Tool Errors
Authors: Dorndorf U. , Kiridena V. S. B. , Ferreira P. M.
Published: April 2008

Quasistatic errors are responsible for a major component of the errors of a numerically controlled machine tool. Such errors are comprised of geometric/kinematic errors, self-induced mechanical strains and thermal strains developed during the operation of the machine. The ability to model the effect of such errors on the volumetric accuracy of a machine tool, opens up the prospect of being able to track and compensate their effects during the operation of the machine. Further, the same model can be used for (cost) optimal allocation of manufacturing and assembly tolerances and specification of operating conditions to get a desired performance. This paper first discusses a model developed for quasistatic static errors and its use as the basis for an optimal error budgeting scheme. Next, the following allocation problem is addressed: Given: (i) a parameter vector whose elements are drawn from normal distributions with unspecified standard deviations and zero means (ii) a set of constraining half spaces defined over parameter space. Specify standard deviations for the distributions so that some function (e.g., the total cost) is minimized. The error model and the error allocation approach are applied to optimal error budgeting. The approach developed is implemented in software and an example of budgeting the geometric errors for a two axis machine is also given. The budgeting procedure developed in this paper can be extended further to subassemblies and components within a machine-tool.
A Solid Modeller Based Milling Process Simulation and Planning System
Authors: Spence A. D. , Altintas Y.
Published: April 2008

A Constructive Solid Geometry (CSG) based process simulation system is developed for 2 1/2 axis milling. Along each path, the cutter is intersected with the individual geometric primitives describing the part. The cutter-part intersection data are then merged using the CSG part description tree, and retained to be accessed during the milling process simulation. Using the stored intersection data and an analytic reformulated mechanistic milling process model, the cutting forces and dimensional accuracy of the parts are simulated before the machining actually takes place. By using an inverse solution for the milling expressions, the feed rate is automatically scheduled to satisfy force, torque, and part dimensional error constraints. The accuracy and efficiency of the milling process simulation model are demonstrated experimentally.
Analysis of Clearance and Rake Angles Along Cutting Edge for Multifacet Drills (MFD)
Authors: Huang Horng-Tsann , Weng Cheng-I , Chen Chao-Kuang
Published: April 2008

Mathematical formulations for the working normal clearance and rake angles along the cutting edges of a multifacet drill (MFD) are developed. The effect of point geometrical parameters of an MFD on the above two angles are described by computer plottings which are the basis for optimizing an MFD. A more precise geometrical model considering a transitional region between the inner cutting edge and are cutting edge is also presented in this paper.
An Analytical Model for Prediction of Tool Temperature Fields during Continuous and Interrupted Cutting
Authors: Radulescu R. , Kapoor S. G.
Published: April 2008

An analytical model for prediction of tool temperature fields in metal cutting processes is developed. The model can be applied to any continuous or interrupted three-dimensional cutting process. To accurately represent the heating and cooling cycles encountered during interrupted cutting, the analysis predicts time dependent heat fluxes into the cutting tool. A time history of this heat flux is obtained by performing an energy balance on the chip formation zone. The variation with time of the tool temperature fields is determined from a heat transfer analysis with prescribed heat generation rate. The analysis requires the cutting forces as inputs. The model tool-chip interface temperatures agree well with the experimental tests reported in the literature, for all cutting conditions and work materials investigated. The results indicate that the tool-chip interface temperature increases with cutting speed during both continuous and interrupted cutting.
Quantitative Measures of Manufacturability for Rotational Parts
Authors: Yannoulakis N. J. , Joshi S. B. , Wysk R. A.
Published: April 2008

This paper addresses the issue of manufacturability measurement for design improvements. With the increasing applications of computer aided engineering, the design engineer must expand the view of design to include ease of manufacturing. Quantitative indicators of manufacturability are the most efficient way of providing manufacturing feedback to the designer. Quantitative measures can be used to indicate redesign targets and rank parts based on ease of manufacturing. A methodology for developing such indicators (manufacturability indices) is presented here, with rotational parts being used as an example. The paper shows how CAD and machining parameters can be utilized to obtain a part’s manufacturing requirements. These requirements are then combined into indices, the use of which is illustrated with examples.
Constant Scallop-height Machining of Free-form Surfaces
Authors: Suresh K. , Yang D. C. H.
Published: April 2008

A novel approach for the NC tool-path generation of free-form surfaces is presented. Traditionally, the distance between adjacent tool-paths in either the Euclidean space or in the parametric space is kept constant. Instead, in this work, the scallop-height is kept constant. This leads to a significant reduction in the size of the CL (cutter location) data accompanied by a reduction in the machining time. This work focuses on the zig-zag (meander) finishing using a ball-end milling cutter.
A Study on Curved Edge Drills
Authors: Han-Min Shi , Hua-Shu Zhang , Liang-Shan Xiong
Published: April 2008

The standard twist drills with curved edges are thoroughly studied in the light of a newly developed technique of displaying and analyzing space angles on cutting tools in a projection plane [1, 2]. The study leads to a full understanding of the relations between the drill point shape and the cutting angle distributions. The study reveals that there exists a special edge line that insures the rake angle at each point reaching its maximum. The technique of optimizing cutting edge shape of a twist drill to realize a desired rake angle distribution is presented. Ways of designing and grinding the flank in order to control the clearance angle are also suggested. Computer software for calculating edge shape from given cutting angle distribution (and vice versa) is developed with the computation results shown. The fundamentals of the study are described, the theoretical and experimental work are presented.
An Analytic Mechanistic Cutting Force Model for Milling Operations: A Case Study of Helical Milling Operation
Authors: Bayoumi A. E. , Yucesan G. , Kendall L. A.
Published: April 2008

The milling force theory developed (Bayoumi et al., 1994) is applied to conventional helical milling operations. Force relationships for this case were obtained. The process parameters were treated as variables, and a methodology to compute them as a function of rotation angle from the sampled force data was developed. Experiments were carried out to test and/or refine the accuracy of the developed force model. The effect of cutting conditions such as radial and axial engagements and cutting speed on the process parameters was investigated. Some cutting tests were carried out using multiedges cutters at different cutting conditions and different tool and workpiece materials to verify the mechanistic model. The predicted results compared well with the experimental measurements.
The Origin and Interpretation of Spatial Frequencies in a Turned Surface Profile
Authors: Moon K. S. , Sutherland J. W.
Published: April 2008

An investigation into the origin of spatial frequencies within a turned surface profile is presented. A wavelength decomposition methodology is used to characterize the wavelength structure of experimental profiles. A model for surface generation in a turning process is described. The model accounts for the stochastic nature and the dynamic response of the cutting process. The model is studied analytically and predictions of the wavelengths in the surface profile are obtained. The model is also examined via computer simulations, and the resulting wavelength predictions are seen to compare favorably with the analytical predictions. Finally, the experimental data and associated wavelength structure are compared to the analytical and simulated results from the model. The model predictions are observed to match, and capture the structure in, the experimentally obtained surface profile data. It is shown that many of the spatial frequencies within a surface profile result from the “sampling” of the radial displacement of the tool relative to the work.