bluuebunny/crossref_metadata_2025 huggingface dataset:
Aging and the Visual, Haptic, and Cross-Modal Perception of Natural Object Shape
Authors: Norman J Farley , Crabtree Charles E , Norman Hideko F , Moncrief Brandon K , Herrmann Molly , Kapley Noah
Published: November 2006

One hundred observers participated in two experiments designed to investigate aging and the perception of natural object shape. In the experiments, younger and older observers performed either a same/different shape discrimination task (experiment 1) or a cross-modal matching task (experiment 2). Quantitative effects of age were found in both experiments. The effect of age in experiment 1 was limited to cross-modal shape discrimination: there was no effect of age upon unimodal (ie within a single perceptual modality) shape discrimination. The effect of age in experiment 2 was eliminated when the older observers were either given an unlimited amount of time to perform the task or when the number of response alternatives was decreased. Overall, the results of the experiments reveal that older observers can effectively perceive 3-D shape from both vision and haptics.
Repetition Priming and Recognition of Dynamic and Static Chimeras
Authors: Steede Leslie L , Hole Graham J
Published: November 2006

Chimeric faces, produced by combining the top half of a familiar face with the bottom half of a different familiar face, are difficult to recognise explicitly. However, given that they contain potentially useful configurational and featural information for face recognition, they might nevertheless produce some activation of representations of their constituent faces. Repetition priming with dynamic and static facial chimeras was used to test this possibility. Whereas half-faces produced significant repetition priming of their familiar counterparts, both types of chimera did not. When analyses were restricted to faces that were recognised during the prime phase, repetition priming was both significant, and equivalent, for chimeras and half-faces. The results suggest that the constituents of a facial chimera must be parsed, and recognised, in order for them to cause repetition priming for their familiar counterparts. Facial motion does not help with the parsing of a facial chimera.
Synesthetically Induced Colors Evoke Apparent-Motion Perception
Authors: Ramachandran Vilayanur S , Azoulai Shai
Published: November 2006

Synesthesia is a condition in which certain otherwise normal individuals see colors when they hear tones, or, when they look at black-and-white numbers, each number is tinged with a specific color (eg 5 is red and 2 is green). We constructed a display in which a random matrix of 5s had a vertical column of 2s ‘embedded’ in it. This was shown in frame 1 of a movie, followed by a similar display in frame 2 in which the element locations were uncorrelated but the bar as a whole was shifted horizontally. When normal subjects viewed the display, they just saw random jitter or twinkle; there was no impression of a bar moving horizontally. But, when our subject (JC) who had grapheme - color synesthesia viewed the display, he reported seeing a bar moving left or right depending on the trial. We conclude that, in at least some subjects, a synesthetically induced color that does not exist on the retina can nonetheless influence motion perception.
Distinct Patterns of Viewpoint-Dependent BOLD Activity during Common-Object Recognition and Mental Rotation
Authors: Wilson Kevin D , Farah Martha J
Published: November 2006

A fundamental but unanswered question about the human visual system concerns the way in which misoriented objects are recognized. One hypothesis maintains that representations of incoming stimuli are transformed via parietally based spatial normalization mechanisms (eg mental rotation) to match view-specific representations in long-term memory. Using fMRI, we tested this hypothesis by directly comparing patterns of brain activity evoked during classic mental rotation and misoriented object recognition involving everyday objects. BOLD activity increased systematically with stimulus rotation within the ventral visual stream during object recognition and within the dorsal visual stream during mental rotation. More specifically, viewpoint-dependent activity was significantly greater in the right superior parietal lobule during mental rotation than during object recognition. In contrast, viewpoint-dependent activity was significantly greater in the right fusiform gyrus during object recognition than during mental rotation. In addition to these differences in viewpoint-dependent activity, object recognition and mental rotation produced distinct patterns of brain activity, independent of stimulus rotation: object recognition resulted in greater overall activity within ventral stream visual areas and mental rotation resulted in greater overall activity within dorsal stream visual areas. The present results are inconsistent with the hypothesis that misoriented object recognition is mediated by structures within the parietal lobe that are known to be involved in mental rotation.
A New Set of Illusions—the Dynamic Luminance-Gradient Illusion and the Breathing Light Illusion
Authors: Gori Simone , Stubbs D Alan
Published: November 2006

A novel set of illusions that break brightness constancy and size constancy at the same time is reported. The illusions occur when observers move towards or away from these patterns. Many variations of these phenomena and a possible explanation are discussed.
Herpes and HIV infection—has the time come to act?
Authors: Russell Darren B.
Published: November 2006

It has been known for some years that the ulcerative and inflammatory STIs lead to an increased risk of HIV transmission. In particular, there is a two- to four-fold increased risk of HIV-1 acquisition associated with prevalent herpes simplex virus type 2. The challenges are discussed herein.
A clinico-aetiological and ultrasonographic study of Peyronie's disease
Authors: Kumar Bhushan , Narang Tarun , Gupta Somesh , Gulati Madhu
Published: November 2006

Background: Peyronie’s disease is a localised connective tissue disorder that involves the tunica albuginea of the penis. Although long recognised as an important clinical entity of the male genitalia, the aetiology of this disease has remained poorly understood. Methods: The epidemiology and clinical presentation of Peyronie’s disease during a 10-year period was evaluated. Results: Forty-two men with Peyronie’s disease from Chandigarh, India were reviewed retrospectively. The prevalence of Peyronie’s patients was 1.97/1000 patients. Their ages ranged from 23 to 70 years. Most of them presented during the early phase of the disease. The most common presenting complaint was penile curvature in 34 (80.95%) followed by pain on erection in 28 (66.66%). History of penile trauma was revealed by four (9.52%) patients. Among the risk factors, hypercholesterolemia (60%), hypertension (33.3%) and asymptomatic hyperuricemia (28.34%) were the most common. Twenty-two patients with Peyronie’s disease were studied by ultrasonography. Ultrasonogram was more accurate than clinical assessment in delineating the extent of lesions. In one-third of the patients, sonography demonstrated the plaques to be more extensive than had been detected by clinical examination. Conclusions: The clinical symptoms and signs in our study were, in general, similar to those found in the previous studies. Higher incidence of hypertension and diabetes in patients with Peyronie’s disease may also be to an extent due to patients being in an older age group.
Estimating population distribution and HIV prevalence among homosexual and bisexual men
Authors: Madeddu Daniel , Grulich Andrew , Richters Juliet , Ferris Jason , Grierson Jeffrey , Smith Anthony , Allan Brent , Prestage Garrett
Published: November 2006

Objectives: To estimate the extent of the homosexual and bisexual male population in inner Sydney and HIV prevalence within this population. Methods: Data from the 2000/2001 Sydney Gay Community Periodic Survey (SGCPS) and the Australian Study of Health and Relationships were used. Results: A re-analysis of responses from men in some inner east and inner west postcode areas of Sydney indicated that: the proportion of men who identified as homosexual or bisexual ranged from 4.4% to 48.1%; from 9.8% to 51.5% of men reported same-sex experiences during their lifetime; and 12.9% to 52.8% of men had ever experienced feelings of same-sex attraction. HIV prevalence among respondents to the SGCPS in these same areas varied from 9.1% to 21.3%. Conclusion: These findings indicate elevated proportions of men with same-sex identity, experience or attraction living in these inner Sydney locations compared with other geographic areas and illustrate how gay communities cluster.
Listening to female sex workers in Vietnam: influences on safe-sex practices with clients and partners
Authors: Rosenthal Doreen , Oanh Tran Thi Kim
Published: November 2006

Background: This qualitative study assessed HIV/AIDS knowledge and frequency of and influences on condom use with clients and regular, non-client partners among female sex workers (FSWs) in Khanh Hoa, a tourist-oriented province of central Vietnam where sex work is common. Methods: Data were collected via semi-structured interviews with indirect (n = 16) and direct (n = 9) FSWs. Results: Although the majority of respondents were well informed about HIV/AIDS transmission, about one-third had inaccurate beliefs about HIV-positive people as well as the mechanisms by which HIV is transmitted from mother to child. Condom use was inconsistent. More direct than indirect FSWs reported using condoms most of the time with clients but none used condoms all the time. With regular partners, most respondents reported that they never used condoms. Around one-third of women hid their sex work from their regular partners, who made the decision to use or not to use condoms. The most frequently reported reasons for not using condoms with clients were because clients offered a higher price, clients insisted on condom-free sex, and possession of condoms as evidence of sex worker status. For regular partners, the reasons were familiarity, condom use being dependent on partner’s decision, and condom use as evidence of sex worker status. There was no apparent relationship between HIV knowledge, time in sex work, and safe sex practices. Conclusion: Recommendations are made to improve the rate of condom use among FSWs.
Human papillomavirus vaccines: challenges to implementation
Authors: Garland Suzanne M.
Published: November 2006

Clinical trials for prophylactic human papillomavirus (HPV) vaccines have shown overwhelmingly positive results. It is expected that with good coverage of the vaccine, 70% of cervical cancers will be prevented, as will a proportion of other HPV-related anogenital diseases. Issues that will require careful consideration will include: whether males and females should be vaccinated; the durability of the immune response; the proportion of attributable disease to the HPV types targetted by the vaccines; and accessibility and cost of the vaccine. Central to an effective vaccination programme will be clear, concise and consistent educative messages regarding HPV not only to the lay public, but also the medical profession.
Social Impacts of Transport Surveillance
Authors: Wigan Marcus , Clarke Roger
Published: November 2006

The transport sector is a natural focal point for surveillance measures to combat the threat of terrorism. It is also a complex environment that offers many examples of the social impacts of contemporary surveillance. Surveillance needs to be assessed against the standards used to justify other forms of security measures. The efficacy of many surveillance schemes, however, is in serious doubt. Justification for these schemes is commonly either lacking entirely or is unpublished and hence has not been subjected to critical evaluation. A small set of mini‐cases is presented, in order to identify the social impacts of twenty‐first century surveillance schemes that have been implemented as fear‐driven responses to terrorist acts. Those impacts are argued to be seriously harmful to society. Trust is crucial to public acceptance of intrusive measures, but the absence of justification for surveillance, and of controls over abuses, is likely to see the rapid dissipation of trust, firstly in the assertions of national security and law enforcement agencies, and secondly in the politicians who have been rubber‐stamping their demands.
Macroinvertebrate community composition relative to chemical/physical variables, land use and cover, and vegetation types within a Lake Michigan drowned river mouth wetland
Authors: Cooper Matthew J. , Uzarski Donald G. , Burton Thomas M. , Rediske Richard R.
Published: November 2006

We analyzed macroinvertebrate community composition from 19 sites, spanning 5 vegetation types, in the White River drowned river mouth wetland (eastern shore of Lake Michigan). Sites were distributed along a gradient of anthropogenic disturbance from the less-impacted upper wetland to the more-impacted lower wetland. The relative importance of surrounding land use and cover, water quality, and vegetation type in structuring macroinvertebrate communities was evaluated using correspondence analysis (CA) of biotic data, and principle components analysis (PCA) of chemical/physical water quality data. A significant correlation (p = 0.001) between site scores of the CA and PCA showed that ambient chemical/physical water quality was likely an important driver of macroinvertebrate community composition. Canonical correspondence analysis (CCA) was then used to corroborate this relationship. Vegetation type, did not appear to structure macroinvertebrate communities to a significant degree. Both water quality and macroinvertebrate community composition correlated with surrounding land use and cover. Therefore, we hypothesize that macroinvertebrate communities in the White River drowned river mouth wetland respond to surrounding land uses via its influence on the abiotic environment. This response occurred even at the within-system scale used in this study. Practitioners of bioassessment protocols should, therefore, be aware of spatial heterogeneity in both water quality and macroinvertebrate community composition in Great Lakes drowned river mouth wetlands.
Challenges of an ecosystem approach to water monitoring and management of the African Great Lakes
Authors: Odada Eric O. , Olago Daniel O.
Published: November 2006

The Great Lakes Belt of Africa cuts across five major drainage basins: The Nile, Congo-Zaire, Rift Valley, Coastal and Zambezi basins. The region contains the earth's largest aggregation of tropical lakes. Three of these lakes–Victoria, Tanganyika and Malawi—hold one quarter of the earth's total surface water supply, and are home to rich and diverse assemblages of fish. Apart from the diversity and endemicity of their biota, properties that distinguish the African Great Lakes from their North American counterparts include their great age, sensitivity to climate change, long residence times, persistent stratification, continuously warm temperatures at all depths, major ion composition, and propensity for nitrogen limitation. Current management problems include over-fishing, increased input of sediment and nutrients, and in the case of Lake Victoria, loss of endemic fish species and the proliferation of the introduced water hyacinth. The harmonization of research programmes and management strategies among the various riparian countries is a challenge. Among the other challenges currently facing the African Great Lakes, perhaps none is more important, nor more often overlooked, than the ecosystem-based management. Ecosystem integrity is beginning to receive acknowledgement in some quarters as a foundation upon which sound management must be built. Recent changes in the African Great Lakes have resulted in an increased realization that individual components of these systems cannot be understood in isolation, and that effective management must expand beyond conventional fisheries management to account for the interaction of physical, geological, chemical and biological processes at the ecosystem scale. Although specific processes in tropical aquatic ecosystems, such as hydrodynamics, plankton production and fisheries production have received some attention, there remains a need to integrate these processes in order to gain a better understanding of ecosystem functioning. One means of achieving this is through the development of conceptual and numerical models, which can facilitate both the theoretical understanding and applied management of these ecosystems. As management problems move from the relatively simple issue of fishery control to the more complex issues of climate change and land use, models will play an important role in decision-making processes regarding sustainable utilization of these vital natural systems.
Fish, fish habitats and fisheries in New Zealand
Authors: McDowall R. M.
Published: November 2006

The origin, ecology, and status of New Zealand's freshwater fisheries resources are reviewed. Rivers are the main freshwater features in these Pacific temperate-zone islands. Geological events, the islands' remoteness, and the recent nature of human colonization (first Maori and then European) have shaped the freshwater ichthyofauna. Diadromy is a dominant ecological feature for many indigenous species. Many species have also been introduced to create fisheries. Traditional Maori fisheries are focussed on indigenous eels and whitebait while recreational fisheries target introduced salmonids. Management of New Zealand freshwater fish is dispersed among several departments. New Zealand habitats are pristine by global standards due largely to the recent settlement of European colonists. Many rivers have been impounded for electricity generation; this constitutes the main environmental issue for freshwater fish. Intensification of agriculture also poses a growing eutrophication threat. The ecologies of indigenous species are becoming better known but much knowledge is anecdotal. Efforts to conserve indigenous freshwater species are increasing. Impoundment, irrigation, deforestation, and introduced salmonids, are the main threats to the native fauna.
Challenges and opportunities for HIV care in jails and prisons in the United States
Authors: De Groot Anne S. , Dilorenzo Madeline , Sylla Mary , Bick Joseph
Published: November 2006

At least 20% of individuals living with HIV pass through prison and jail doors every year, in any nation, worldwide. Therefore, interventions that improve access to HIV testing, HIV care, and education can have a broad impact on public health in every country. The benefits of these interventions in correctional settings have already been well documented. For example, improved access to HIV testing, treatment by an HIV specialist, preventive vaccinations and prophylactic medications, screening for concomitant infections such as HCV, and pre‐release planning services have been shown to decrease HIV‐related mortality and morbidity, to reduce the risk of HIV transmission and to decrease recidivism. Education of at‐risk individuals has also been shown to reduce HIV risk behaviors. Safe distribution of condoms and needle‐exchange programs have also been demonstrated to be safe and effective, although few such programs have been implemented in the United States. While all the available evidence has demonstrated that these public health‐oriented interventions can be and are successful in correctional settings, implementation on a national and international level lags far behind the evidence. The time has come to take an evidence‐based approach to improving HIV management in correctional settings. Implementations of the HIV management interventions described in this article make good medical sense and will have a positive impact on the health of inmates and the communities to which inmates return.
People with problematic drug use and HIV/AIDS in European prisons: An issue of patient confidentiality
Authors: MacDonald Morag
Published: November 2006

Research has shown that a key issue for prisoners using healthcare services during their sentence is that of patient confidentiality. Maintaining prisoners’ medical confidentiality has been shown to be difficult in the prison setting as many treatments, especially those considered to be out of the ordinary, are more likely to result in a breach of medical confidence. This can include treating infectious diseases, such as HIV/AIDS, Hepatitis or tuberculosis, which can often include long term and regular contact with healthcare staff, and which, in some cases, may require referrals to specialists outside the prison setting. In addition, institutional factors unique to prisons may impact on healthcare staffs’
ability to maintain prisoners’ confidentiality, such as security or health and safety concerns. Drawing on research carried out by the author on healthcare and people with problematic drug use in prisons in a range of European countries, this paper considers the factors that impact on maintaining prisoners’ medical confidentiality and some of the attempts to address this issue.
HIV/AIDS and HCV in prisons: A select annotated bibliography (part 3)
Authors: Jürgens Ralf
Published: November 2006

Since the early 1990s, various countries have introduced HIV prevention programmes in prisons. Such programmes include education on HIV/AIDS, HCV and on drug use for prisoners and for staff, voluntary testing and counselling, the distribution of condoms, bleach, and needles and syringes, and substitution therapy for injecting drug users. Other forms of drug‐dependence treatment, as well as drug demand reduction and drug supply reduction measures may also be relevant to managing HIV/AIDS and HCV in prisons, and may facilitate HIV prevention measures ‐ or have unintended negative consequences for such measures. Prison systems in a growing number of countries are implementing such programmes. However, many of them are small in scale and restricted to a few prisons. Provision of care and treatment for people living with HIV or AIDS has become a priority
worldwide, and it is considered to be a basic human right. This includes the provision of antiretroviral therapy (ARV) in the context of comprehensive HIV/AIDS care. Providing access to ARV for those in need in the context of correctional facilities is a challenge, but it is necessary and feasible. Studies have documented that, when provided with care and access to medications, prisoners respond well to ARV. Part 3 of the select annotated bibliography on HIV/AIDS and HCV in prisons contains selected “essential” articles and reports that provide information about (1) substitution treatment and other forms of drug‐dependence treatment; (2) other drug demand and drug supply reduction measures; and (3) care, treatment, and support for prisoners living with HIVor AIDS and/or HCV. Each section also contains a brief review of the evidence, based on recent work undertaken by the World Health Organization (WHO).
Building an effective international framework to address HIV/AIDS in prisons
Authors: Lines Rick , Stöver Heino
Published: November 2006

HIV/AIDS is a serious health threat for prison populations in many countries, and presents significant challenges for prison and public health authorities. This situation is often exacerbated by high rates of hepatitis and/or tuberculosis. The generally accepted principle that prisons and prisoners remain part of the broader community means that the health threat of HIV within prisons, and the health threat outside of prisons, are inextricably linked and demand coordinated action. Yet many countries have not implemented comprehensive HIV prevention programmes in prisons, or achieved a standard of prison healthcare equivalent to the standard outside of prison. In December 2004, the authors were retained by the United Nations Office on Drugs and Crime (UNODC) to prepare an international Framework to address HIV/AIDS prevention, care and treatment in prisons. The Framework is a tool
designed to assist governments meet international obligations on human rights, prison conditions, and public health. It outlines a 100‐point action plan for implementing a response to HIV/AIDS in prisons based on international health and human rights standards, and on evaluated models of good practice.
Indonesian National Strategy for HIV/AIDS control in prisons: A public health approach for prisoners
Authors: Winarso Inang , Irawati Ingrid , Eka Bambang , Nevendorff Laura , Handoyo Patri , Salim Hendra , Mesquita Faboi
Published: November 2006

There were 89,708 prisoners in Indonesia in April 2006. The majority were charged for narcotics related crimes. Prisons are working at over‐capacity and with miniscule healthcare budgets. There has been an increase of deaths due to AIDS, particularly among people who inject drugs. Official data shows that HIV prevalence averages 22% in prisons. In late 2002, the Ministry of Justice (MOJ) decided to promote HIV/AIDS prevention and care activities for prisoners to prevent the spread of HIV within prisons, and from there to the community as a whole. In 2005, MOJ launched the Indonesian National Strategy for HIV/AIDS Prevention, Care and Support for Prisoners. The Indonesian HIV/AIDS Prevention and Care Project has been actively involved in the design of these programs and supported their implementation in several prisons, together with other organizations. The Indonesian National Strategy is the first of its kind in Asia, and one of only a few dedicated national strategies for HIV/AIDS prevention and care for prisoners. It has enabled education, as well as the provision of condoms, bleach, methadone and antiretroviral therapy for prisoners. This paper describes the National Strategy for HIV/AIDS Prevention, Care and Support for Prisoners, which will help control the HIVepidemic among people who inject drugs and ultimately be beneficial for the community as a whole.
Transport of LAPTM5 to lysosomes requires association with the ubiquitin ligase Nedd4, but not LAPTM5 ubiquitination
Authors: Pak Youngshil , Glowacka Wioletta K. , Bruce M. Christine , Pham Nam , Rotin Daniela
Published: November 2006

LAPTM5 is a lysosomal transmembrane protein expressed in immune cells. We show that LAPTM5 binds the ubiquitin-ligase Nedd4 and GGA3 to promote LAPTM5 sorting from the Golgi to the lysosome, an event that is independent of LAPTM5 ubiquitination. LAPTM5 contains three PY motifs (L/PPxY), which bind Nedd4-WW domains, and a ubiquitin-interacting motif (UIM) motif. The Nedd4–LAPTM5 complex recruits ubiquitinated GGA3, which binds the LAPTM5-UIM; this interaction does not require the GGA3-GAT domain. LAPTM5 mutated in its Nedd4-binding sites (PY motifs) or its UIM is retained in the Golgi, as is LAPTM5 expressed in cells in which Nedd4 or GGA3 is knocked-down with RNAi. However, ubiquitination-impaired LAPTM5 can still traffic to the lysosome, suggesting that Nedd4 binding to LAPTM5, not LAPTM5 ubiquitination, is required for targeting. Interestingly, Nedd4 is also able to ubiquitinate GGA3. These results demonstrate a novel mechanism by which the ubiquitin-ligase Nedd4, via interactions with GGA3 and cargo (LAPTM5), regulates cargo trafficking to the lysosome without requiring cargo ubiquitination.
The major human and mouse granzymes are structurally and functionally divergent
Authors: Kaiserman Dion , Bird Catherina H. , Sun Jiuru , Matthews Antony , Ung Kheng , Whisstock James C. , Thompson Philip E. , Trapani Joseph A. , Bird Phillip I.
Published: November 2006

Approximately 2% of mammalian genes encode proteases. Comparative genomics reveals that those involved in immunity and reproduction show the most interspecies diversity and evidence of positive selection during evolution. This is particularly true of granzymes, the cytotoxic proteases of natural killer cells and CD8+ T cells. There are 5 granzyme genes in humans and 10 in mice, and it is suggested that granzymes evolve to meet species-specific immune challenge through gene duplication and more subtle alterations to substrate specificity. We show that mouse and human granzyme B have distinct structural and functional characteristics. Specifically, mouse granzyme B is 30 times less cytotoxic than human granzyme B and does not require Bid for killing but regains cytotoxicity on engineering of its active site cleft. We also show that mouse granzyme A is considerably more cytotoxic than human granzyme A. These results demonstrate that even “orthologous” granzymes have species-specific functions, having evolved in distinct environments that pose different challenges.
Comparative proteomics of clathrin-coated vesicles
Authors: Borner Georg H.H. , Harbour Michael , Hester Svenja , Lilley Kathryn S. , Robinson Margaret S.
Published: November 2006

Clathrin-coated vesicles (CCVs) facilitate the transport of cargo between the trans-Golgi network, endosomes, and the plasma membrane. This study presents the first comparative proteomics investigation of CCVs. A CCV-enriched fraction was isolated from HeLa cells and a “mock CCV” fraction from clathrin-depleted cells. We used a combination of 2D difference gel electrophoresis and isobaric tags for relative and absolute quantification (iTRAQ) in conjunction with mass spectrometry to analyze and compare the two fractions. In total, 63 bona fide CCV proteins were identified, including 28 proteins whose association with CCVs had not previously been established. These include numerous post-Golgi SNAREs; subunits of the AP-3, retromer, and BLOC-1 complexes; lysosomal enzymes; CHC22; and five novel proteins of unknown function. The strategy outlined in this paper should be widely applicable as a means of distinguishing genuine organelle components from contaminants.
Simple kinetic relationships and nonspecific competition govern nuclear import rates in vivo
Authors: Timney Benjamin L. , Tetenbaum-Novatt Jaclyn , Agate Diana S. , Williams Rosemary , Zhang Wenzhu , Chait Brian T. , Rout Michael P.
Published: November 2006

Many cargoes destined for nuclear import carry nuclear localization signals that are recognized by karyopherins (Kaps). We present methods to quantitate import rates and measure Kap and cargo concentrations in single yeast cells in vivo, providing new insights into import kinetics. By systematically manipulating the amounts, types, and affinities of Kaps and cargos, we show that import rates in vivo are simply governed by the concentrations of Kaps and their cargo and the affinity between them. These rates fit to a straightforward pump–leak model for the import process. Unexpectedly, we deduced that the main limiting factor for import is the poor ability of Kaps and cargos to find each other in the cytoplasm in a background of overwhelming nonspecific competition, rather than other more obvious candidates such as the nuclear pore complex and Ran. It is likely that most of every import round is taken up by Kaps and nuclear localization signals sampling other cytoplasmic proteins as they locate each other in the cytoplasm.
A monoidal approach to splitting morphisms of bialgebras
Authors: Ardizzoni A. , Menini C. , Ştefan D.
Published: November 2006

The main goal of this paper is to investigate the structure of Hopf algebras with the property that either its Jacobson radical is a Hopf ideal or its coradical is a subalgebra. Let us consider a Hopf algebra

A
A

such that its Jacobson radical

J
J

is a nilpotent Hopf ideal and

H
:=
A

/

J

H:=A/J

is a semisimple algebra. We prove that the canonical projection of

A
A

on

H
H

has a section which is an

H
H

–colinear algebra map. Furthermore, if

H
H

is cosemisimple too, then we can choose this section to be an

(
H
,
H
)

(H,H)

–bicolinear algebra morphism. This fact allows us to describe

A
A

as a ‘generalized bosonization’ of a certain algebra

R
R

in the category of Yetter–Drinfeld modules over

H
H

. As an application we give a categorical proof of Radford’s result about Hopf algebras with projections. We also consider the dual situation. Let

A
A

be a bialgebra such that its coradical is a Hopf sub-bialgebra with antipode. Then there is a retraction of the canonical injection of

H
H

into

A
A

which is an

H
H

–linear coalgebra morphism. Furthermore, if

H
H

is semisimple too, then we can choose this retraction to be an

(
H
,
H
)

(H,H)

–bilinear coalgebra morphism. Then, also in this case, we can describe

A
A

as a ‘generalized bosonization’ of a certain coalgebra

R
R

in the category of Yetter–Drinfeld modules over

H
H

.
Toric hypersymplectic quotients
Authors: Dancer Andrew , Swann Andrew
Published: November 2006

We study the hypersymplectic spaces obtained as quotients of flat hypersymplectic space

R

4
d

\mathbb {R}^{4d}

by the action of a compact Abelian group. These

4
n

4n

-dimensional quotients carry a multi-Hamilitonian action of an

n
n

-torus. The image of the hypersymplectic moment map for this torus action may be described by a configuration of solid cones in

R

3
n

\mathbb {R}^{3n}

. We give precise conditions for smoothness and non-degeneracy of such quotients and show how some properties of the quotient geometry and topology are constrained by the combinatorics of the cone configurations. Examples are studied, including non-trivial structures on

R

4
n

\mathbb {R}^{4n}

and metrics on complements of hypersurfaces in compact manifolds.
Small ball probabilities for the Slepian Gaussian fields
Authors: Gao Fuchang , Li Wenbo
Published: November 2006

The

d
d

-dimensional Slepian Gaussian random field

{
S
(

t

)
,

t

∈

R

+
d

}

\{S({\mathbf {t}}), {\mathbf {t}} \in \mathbb {R}_+^d\}

is a mean zero Gaussian process with covariance function
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="double-struck upper E upper S left-parenthesis bold s right-parenthesis upper S left-parenthesis bold t right-parenthesis equals product Underscript i equals 1 Overscript d Endscripts max left-parenthesis 0 comma a Subscript i Baseline minus StartAbsoluteValue s Subscript i Baseline minus t Subscript i Baseline EndAbsoluteValue right-parenthesis">

E

S
(

s

)
S
(

t

)
=

∏

i
=
1

d

max
(
0
,

a
i

−

|

s
i

−

t
i

|

)

\mathbb {E} S({\mathbf {s}})S({\mathbf {t}})= \prod _{i=1}^d \max (0, a_i-\left | s_i-t_i\right | )

for

a
i

>
0

a_i>0

and

t

=
(

t
1

,
⋯
,

t
d

)
∈

R

+
d

{\mathbf {t}}=(t_1, \cdots , t_d) \in \mathbb {R}_+^d

. Small ball probabilities for

S
(

t

)

S({\mathbf {t}})

are obtained under the

L
2

L_2

-norm on

[
0
,
1

]
d

[0,1]^d

, and under the sup-norm on

[
0
,
1

]
2

[0,1]^2

which implies Talagrand’s result for the Brownian sheet. The method of proof for the sup-norm case is purely probabilistic and analytic, and thus avoids ingenious combinatoric arguments of using decreasing mathematical induction. In particular, Riesz product techniques are new ingredients in our arguments.
Closed form summation of 𝐶-finite sequences
Authors: Greene Curtis , Wilf Herbert
Published: November 2006

We consider sums of the form
\[
<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="sigma-summation Underscript j equals 0 Overscript n minus 1 Endscripts upper F 1 left-parenthesis a 1 n plus b 1 j plus c 1 right-parenthesis upper F 2 left-parenthesis a 2 n plus b 2 j plus c 2 right-parenthesis ellipsis upper F Subscript k Baseline left-parenthesis a Subscript k Baseline n plus b Subscript k Baseline j plus c Subscript k Baseline right-parenthesis comma">

∑

j
=
0

n
−
1

F
1

(

a
1

n
+

b
1

j
+

c
1

)

F
2

(

a
2

n
+

b
2

j
+

c
2

)
…

F
k

(

a
k

n
+

b
k

j
+

c
k

)
,

\sum _{j=0}^{n-1}F_1(a_1n+b_1j+c_1)F_2(a_2n+b_2j+c_2)\dots F_k(a_kn+b_kj+c_k),

\]
in which each

{

F
i

(
n
)
}

\{F_i(n)\}

is a sequence that satisfies a linear recurrence of degree

D
(
i
)
>
∞

D(i)>\infty

, with constant coefficients. We assume further that the

a
i

a_i

’s and the

a
i

+

b
i

a_i+b_i

’s are all nonnegative integers. We prove that such a sum always has a closed form, in the sense that it evaluates to a linear combination of a finite set of monomials in the values of the sequences

{

F
i

(
n
)
}

\{F_i(n)\}

with coefficients that are polynomials in

n
n

. We explicitly describe two different sets of monomials that will form such a linear combination, and give an algorithm for finding these closed forms, thereby completely automating the solution of this class of summation problems. We exhibit tools for determining when these explicit evaluations are unique of their type, and prove that in a number of interesting cases they are indeed unique. We also discuss some special features of the case of “indefinite summation", in which

a
1

=

a
2

=
⋯
=

a
k

=
0

a_1=a_2=\cdots = a_k = 0

.
The classification of singly periodic minimal surfaces with genus zero and Scherk-type ends
Authors: Pérez Joaquín , Traizet Martin
Published: November 2006

Given an integer

k
≥
2

k\geq 2

, let

S

(
k
)

{\mathcal S}(k)

be the space of complete embedded singly periodic minimal surfaces in

R

3

\mathbb {R}^3

, which in the quotient have genus zero and

2
k

2k

Scherk-type ends. Surfaces in

S

(
k
)

{\mathcal S}(k)

can be proven to be proper, a condition under which the asymptotic geometry of the surfaces is well known. It is also known that

S

(
2
)

{\mathcal S}(2)

consists of the

1
1

-parameter family of singly periodic Scherk minimal surfaces. We prove that for each

k
≥
3

k\geq 3

, there exists a natural one-to-one correspondence between

S

(
k
)

{\mathcal S}(k)

and the space of convex unitary nonspecial polygons through the map which assigns to each

M
∈

S

(
k
)

M\in {\mathcal S}(k)

the polygon whose edges are the flux vectors at the ends of

M
M

(a special polygon is a parallelogram with two sides of length

1
1

and two sides of length

k
−
1

k-1

). As consequence,

S

(
k
)

{\mathcal S}(k)

reduces to the saddle towers constructed by Karcher.
Counterexamples to the poset conjectures of Neggers, Stanley, and Stembridge
Authors: Stembridge John
Published: November 2006

We provide the first counterexamples to Neggers’ 1978 conjecture and Stembridge’s 1997 conjecture that the generating functions for descents and peaks in the linear extensions of naturally labeled posets should have all real zeros. We also provide minimum-sized counterexamples to a generalization of the Neggers conjecture due to Stanley that was recently disproved by Brändén.
On Lorentz dynamics: From group actions to warped products via homogeneous spaces
Authors: Arouche A. , Deffaf M. , Zeghib A.
Published: November 2006

We show a geometric rigidity of isometric actions of non-compact (semisimple) Lie groups on Lorentz manifolds. Namely, we show that the manifold has a warped product structure of a Lorentz manifold with constant curvature by a Riemannian manifold.
Invariance principles for iterated maps that contract on average
Authors: Walkden C.
Published: November 2006

We consider iterated function schemes that contract on average. Using a transfer operator approach, we prove a version of the almost sure invariance principle. This allows the system to be modelled by a Brownian motion, up to some error term. It follows that many classical statistical properties hold for such systems, such as the weak invariance principle and the law of the iterated logarithm.
Conflict between direct and indirect benefits of female choice in desertDrosophila
Authors: Oneal Elen , Connallon Tim , Lacey Knowles L
Published: November 2006

Identifying the factors that contribute to the adaptive significance of mating preferences is one major goal of evolutionary research and is largely unresolved. Both direct and indirect benefits can contribute to mate choice evolution. Failure to consider the interaction between individual consequences of mate choice may obscure the opposing effects of individual costs and benefits. We investigate direct and indirect fitness effects of female choice in a desert fly (Drosophila mojavensis), a species where mating confers resistance to desiccation stress. Females prefer males that provide a direct benefit: greater resistance to desiccation stress. Mating preferences also appear to have indirect consequences: daughters of preferred males have lower reproductive success than daughters of unpreferred males, although additional experimentation will be needed to determine if the indirect consequences of female preferences actually arise from ‘sexually antagonistic’ variation. Nevertheless, the results are intriguing and are consistent with the hypothesis that an interaction between direct and indirect benefits maintains sexually antagonistic variation in these desert flies: increased desiccation resistance conferred by mating might offset the cost of producing low-fecundity daughters.
Multimodal pattern formation in phenotype distributions of sexual populations
Authors: Doebeli Michael , Blok Hendrik J , Leimar Olof , Dieckmann Ulf
Published: November 2006

During bouts of evolutionary diversification, such as adaptive radiations, the emerging species cluster around different locations in phenotype space. How such multimodal patterns in phenotype space can emerge from a single ancestral species is a fundamental question in biology. Frequency-dependent competition is one potential mechanism for such pattern formation, as has previously been shown in models based on the theory of adaptive dynamics. Here, we demonstrate that also in models similar to those used in quantitative genetics, phenotype distributions can split into multiple modes under the force of frequency-dependent competition. In sexual populations, this requires assortative mating, and we show that the multimodal splitting of initially unimodal distributions occurs over a range of assortment parameters. In addition, assortative mating can be favoured evolutionarily even if it incurs costs, because it provides a means of alleviating the effects of frequency dependence. Our results reveal that models at both ends of the spectrum between essentially monomorphic (adaptive dynamics) and fully polymorphic (quantitative genetics) yield similar results. This underscores that frequency-dependent selection is a strong agent of pattern formation in phenotype distributions, potentially resulting in adaptive speciation.
Reproduction and modulation of the stress response: an experimental test in the house sparrow
Authors: Lendvai Ádám Zoltán , Giraudeau Mathieu , Chastel Olivier
Published: November 2006

The stress response is highly variable among individuals, but the causes of this variation remain largely unknown. In response to stressors, vertebrates secrete elevated levels of glucocorticoids which enhance survival, but concurrently interfere with reproduction. We tested the hypothesis that individuals flexibly modulate their stress response with respect to the reproductive value of their brood in free-living house sparrows (
Passer domesticus
). We experimentally increased or decreased clutch size during the nestling period and found that parents tending enlarged clutches responded less strongly to a stressor than those tending reduced clutches. In addition, we examined whether individuals responded less strongly to a stressor as the breeding season progressed and future reproductive opportunities declined. We found that the stress response decreased with breeding date during the birds' first breeding attempt, but it remained constant during their second breeding attempt. Within-individual variability in the stress response was related to the brood size manipulations the birds received in their two consecutive breeding attempts. These results provide the first experimental support for the hypothesis that individuals actively modulate their stress response with respect to the value of current reproduction.
Temporal and spatial variation in age-specific survival rates of a long-lived mammal, the Hawaiian monk seal
Authors: Baker Jason D , Thompson Paul M
Published: November 2006

Estimates of variability in pinniped survival rates are generally based on observations at single sites, so it is not certain whether observed rates represent the whole population. Here, we provide a comprehensive analysis of spatio-temporal variation in age-specific survival rates for endangered Hawaiian monk seals (Monachus schauinslandi) based on capture–recapture analyses of more than 85% of the pups weaned in this population over the last two decades. Uniquely, these data have been collected from six subpopulations, encompassing all major breeding sites across its 1800 km long core range. Analyses of individual subpopulations revealed similar patterns in age-specific survival, characterized by the relatively low survival rates from weaning to 2 years of age, intermediate rates to 4 years of age, and then by relatively high ‘mature’ survival rates until 17 years of age, after which a senescent decline was observed. Juvenile, subadult and adult survival rates all varied significantly over time. Trends in survival among subpopulations were coherent with their relative geographical positions, suggesting regional structuring and connectedness within the archipelago. Survival rates for different age classes tended to be positively correlated, suggesting that similar factors may influence the survival for seals of all ages.
Selection against males inCaenorhabditis elegansunder two mutational treatments
Authors: Manoel Diogo , Carvalho Sara , Phillips Patrick C , Teotónio Henrique
Published: November 2006

Within populations with mixed mating systems, selfing is expected to be favoured over outcrossing unless a countervailing process such as severe inbreeding depression is present. In this study, we consider the relationship between the expression of deleterious alleles and the maintenance of outcrossing in the nematode species,Caenorhabditis elegans. This species is characterized by an androdioecious breeding system composed of males at low frequency and self-fertilizing hermaphrodites that can only outcross via males. Here, we find that experimentally increasing the mutational load in four different isogenic wild isolates using 10 generations of Ethylmethane sulphonate (EMS) and UV irradiation mutagenesis significantly diminishes the cost of males. Males are maintained at higher frequencies in mutagenized versus non-mutagenized populations. Nevertheless, males still tend to be driven to low frequencies within isolates that are known to be prone to lose males. Further, we determine the viability effects of a single round of mutagen exposure and find that, for EMS, outcrossing overcomes the almost completely recessive and nearly lethal effects generated. We briefly interpret our results in light of current evolutionary theory of outcrossing rates.