bluuebunny/crossref_metadata_2025 huggingface dataset:
Raman and X‐ray photoelectron spectroscopy investigation of the effect of gamma‐ray irradiation on MoS2
Authors: Ozden Burcu , Khanal Min P. , Park Juhong , Uprety Sunil , Mirkhani Vahid , Yapabandara Kosala , Kim Kyunghyuk , Kuroda Marcelo , Bozack Michael J. , Choi Wonbong , Park Minseo
Published: December 2016

The effect of gamma‐ray (γ‐ray) irradiation on the material characteristics of nanometre scale films of molybdenum disulphide (MoS2) has been investigated. 3.2, 4.5, and 5.2 nm thick MoS2 films (measured by atomic force microscopy) were grown on Si by using a two‐step synthesis method (sputtering of Mo, followed by sulphurisation). The samples were subsequently exposed to γ‐ray irradiation (dose of 120 MRad). Dramatic chemical changes in the MoS2 films after irradiation were characterised by micro‐Raman spectroscopy, X‐ray photoelectron spectroscopy (XPS), and optical microscopy. Micro‐Raman spectroscopy showed the disappearance of the E2g1 and A1g modes after irradiation. XPS revealed that the MoS2 crystal structure was converted to molybdenum oxide (MoOx). It is hypothesised that S vacancies are formed due to the γ‐ray irradiation, which subsequently transforms MoS2 to MoOx.
Fluorescent Ion Efflux Screening Assay for Determining Membrane-Active Peptides
Authors: O'Brien-Simpson Neil M. , Li Wenyi , Pantarat Namfon , Hossain Mohammed Akhter , Separovic Frances , Wade John D. , Reynolds Eric C.
Published: December 2016

A major global health threat is the emergence of antibiotic-resistant microbes. Coupled with a lack of development of modified antibiotics, there is a need to develop new antimicrobial molecules and screening assays for them. In this study, we provide proof of concept that a large unilamellar vesicle (LUV) method used to study chloride ion efflux facilitated by ionophores and surfactant-like molecules that disrupt membrane integrity can be adapted to identify membrane-interactive antimicrobial peptides (AMPs) and to screen relative activity of AMPs. Lucigenin was encapsulated in LUVs in the presence of Cl– ion (NaCl), which quenches fluorescence, and then incubated with AMPs in 100 mM NaNO3 buffer. Upon AMP membrane interaction or disruption, the Cl– ion is exchanged with the NO3– ion, and the resultant lucigenin fluorescence is indicative of relative AMP activity. Seven AMPs were synthesized by solid-phase peptide chemistry and incubated with LUVs of different phospholipid compositions. Each AMP resulted in lucigenin fluorescence, which was dose dependent, and the relative fluorescence correlated with the minimum inhibitory concentration and minimum bactericidal concentration values for the corresponding peptide. Furthermore, using mammalian model phospholipid LUVs, lucigenin-induced fluorescence also correlated with the AMP cytotoxicity half-maximal inhibitory concentration values. The proline-rich AMP, Chex1-Arg20, which is non-lytic but interacts with the bacterial membrane resulted in lucigenin fluorescence of bacterial membrane model LUVs but not of mammalian membrane model LUVs. The fluorescent ion efflux assay developed here should have applicability for most AMPs and could be tailored to target particular bacterial species membrane composition, potentially leading to the identification of novel membrane-interactive AMPs. The rapid high-throughput method also allows for screening of relative AMP activity and toxicity before biological testing.
Vulnerability of fish and macroinvertebrates to key threats in streams of the Kakadu region, northern Australia: assemblage dynamics, existing assessments and knowledge needs
Authors: Humphrey Chris L. , Bishop Keith A. , Dostine Peter L.
Published: December 2016

By 2100, it is predicted that streams in the Kakadu region in Northern Australia will be transforming in their coastal floodplains to saline environments because of sea-level rise. Potential impacts need to be assessed, together with existing threats, to manage future change. The fish and macroinvertebrate assemblages of the streams in the region are well researched and were used as indicators to assess centennial-scale changes to freshwaters. Spatial and temporal patterns in assemblage dynamics were described using data from different habitat types, and used as a framework to review current knowledge and assemblage vulnerability for likely conditions ≥100 years from present-day. Twenty threats within three broad classes were identified (climate change, invasive species, decommissioning and rehabilitation of Ranger uranium mine). Seven threatening processes were ranked as high risk to catchment-scale distributions of fish and macroinvertebrate taxa, with six being associated with climate change and one with mine-site rehabilitation. Habitat connectivities and dependencies were identified as key ecological processes for both groups, with saltwater intrusion to coastal floodplains being identified as the major process that will alter assemblage dynamics and system energy flow. Risks posed by climate change highlighted priority research and monitoring needs for management and protection of upland freshwater-refuge habitats.
Structural basis of influenza virus fusion inhibition by the antiviral drug Arbidol
Authors: Kadam Rameshwar U. , Wilson Ian A.
Published: December 2016

Significance

Influenza virus is an important human pathogen. The circulating strains of influenza virus are constantly mutating and are acquiring resistance to all approved drugs. Therefore, development of influenza therapeutics against novel targets is urgently required. The hemagglutinin envelope glycoprotein (HA) is a promising target for small-molecule design. However, Arbidol is the only available antiviral drug that targets the HA. The absence of structural information on drug–HA complexes has hindered further therapeutic development efforts against this viral pathogen. Here, we report crystal structures of Arbidol in complex with influenza HAs. This structural information advances our understanding of how small molecules, such as Arbidol, can function as influenza fusion inhibitors and can be used for development of broad-spectrum, small-molecule therapeutics.
Nat1
promotes translation of specific proteins that induce differentiation of mouse embryonic stem cells
Authors: Sugiyama Hayami , Takahashi Kazutoshi , Yamamoto Takuya , Iwasaki Mio , Narita Megumi , Nakamura Masahiro , Rand Tim A. , Nakagawa Masato , Watanabe Akira , Yamanaka Shinya
Published: December 2016

Significance

We have previously shown that novel APOBEC1 target 1 (NAT1), which is homologous to the C-terminal two thirds of eukaryotic translation initiation factor 4G (eIF4G), is essential for differentiation of mouse embryonic stem cells (mES cells). In the current study, we demonstrate that
Nat1
supports the translation of mitogen-activated protein kinase kinase kinase 3 (
Map3k3
) and son of sevenless homolog 1 (
Sos1
). Deletion of
Nat1
resulted in decreased protein levels of these factors, resulting in suppression of the
Erk
and
Akt
signaling pathway. Forced expression of
Map3k3
induced differentiation in
Nat1
-null mES cells. Thus
Nat1
is involved in the translation of proteins that are required for the differentiation of mES cells.
Ultrastructural anatomy of nodes of Ranvier in the peripheral nervous system as revealed by STED microscopy
Authors: D’Este Elisa , Kamin Dirk , Balzarotti Francisco , Hell Stefan W.
Published: December 2016

Significance

In vertebrates, the action potential travels along myelin-coated electrically isolated axons and is regenerated at the nodes of Ranvier, which lack myelination and are characterized by a tight interaction between the axon and glial cells. Specific sets of proteins are enriched in each region of the nodes. Thanks to its subdiffraction resolution, stimulated emission depletion (STED) microscopy here uncovers the organization of 12 of these proteins at the nanoscale. The superresolved imaging reveals an extremely fine interplay and alignment of the axonal and glial cytoskeleton, with a defined ∼190-nm periodicity. Furthermore, the results point to the importance of the lateral organization of proteins at nodal gaps, an aspect that is yet unexplored.
Progress toward active or passive HIV-1 vaccination
Authors: Escolano Amelia , Dosenovic Pia , Nussenzweig Michel C.
Published: December 2016

AIDS is a preventable disease. Nevertheless, according to UNAIDS, 2.1 million individuals were infected with HIV-1 in 2015 worldwide. An effective vaccine is highly desirable. Most vaccines in clinical use today prevent infection because they elicit antibodies that block pathogen entry. Consistent with this general rule, studies in experimental animals have shown that broadly neutralizing antibodies to HIV-1 can prevent infection, suggesting that a vaccine that elicits such antibodies would be protective. However, despite significant efforts over the last 30 years, attempts to elicit broadly HIV-1 neutralizing antibodies by vaccination failed until recent experiments in genetically engineered mice were finally successful. Here, we review the key breakthroughs and remaining obstacles to the development of active and passive HIV-1 vaccines.
Generalized Nehari manifold and semilinear Schrödinger equation with weak monotonicity condition on the nonlinear term
Authors: de Paiva Francisco , Kryszewski Wojciech , Szulkin Andrzej
Published: December 2016

We study the Schrödinger equations

−
Δ
u
+
V
(
x
)
u
=
f
(
x
,
u
)

-\Delta u + V(x)u = f(x,u)

in

R

N

\mathbb {R}^N

and

−
Δ
u
−
λ
u
=
f
(
x
,
u
)

-\Delta u - \lambda u = f(x,u)

in a bounded domain

Ω
⊂

R

N

\Omega \subset \mathbb {R}^N

. We assume that

f
f

is superlinear but of subcritical growth and

u
↦
f
(
x
,
u
)

/

|

u

|

u\mapsto f(x,u)/|u|

is nondecreasing. In

R

N

\mathbb {R}^N

we also assume that

V
V

and

f
f

are periodic in

x
1

,
…
,

x
N

x_1,\ldots ,x_N

. We show that these equations have a ground state and that there exist infinitely many solutions if

f
f

is odd in

u
u

. Our results generalize those by Szulkin and Weth [J. Funct. Anal. 257 (2009), 3802–3822], where

u
↦
f
(
x
,
u
)

/

|

u

|

u\mapsto f(x,u)/|u|

was assumed to be strictly increasing. This seemingly small change forces us to go beyond methods of smooth analysis.
Unlikely intersections for curves in additive groups over positive characteristic
Authors: Brownawell W. , Masser D.
Published: December 2016

The conjectures associated with the names of Zilber-Pink greatly generalize results associated with the names of Manin-Mumford and Mordell-Lang, but unlike the latter they are at present restricted to zero characteristic. Recently the second author made a start on removing this restriction by studying multiplicative groups over positive characteristic, and here we go further for additive groups with extra Frobenius structure. We state a conjecture for curves in general dimension and we prove it in three dimensions. We also give an example where the finite set in question can be explicitly determined.
Communication on Climate Change and Energy Alternatives in the United States
Authors: Bolsen Toby , Shapiro Matthew A.
Published: December 2016

This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Climate Science. Please check back later for the full article.

Most of what people think about politics comes from information acquired via exposure to mass media. Media thus serve a vital role in democracy as a fundamental conduit of political information. Scholars study the factors that drive news coverage about political issues, including the rise of discourse on climate change and shifts in media coverage over time. Climate change first received sustained attention in the U.S. press in the late 1980s and early 1990s. As scientific consensus emerged on the issue, interest groups and other actors emerged who accentuated the inherent uncertainty of climate science as a way to cast doubt on the existence of scientific consensus. The politicization of climate science has resulted in uncertainty among the public about its existence, anxiety about the effects of a fundamental transformation of U.S. energy systems, and support for the status quo in terms of the use of traditional energy sources. Media coverage often magnified the voices of contrarian scientists and skeptics because journalistic norms provided equal space to all sides, a semblance of false balance in news coverage that has persisted through the mid 2000s. By this time, the U.S. public had fractured along partisan lines due to rhetoric employed to generate support by elites. Media fragmentation and the rise of partisan news outlets further contributed to polarization, especially given the tendency of individuals to seek political information about climate change from trusted and credible sources. More recently, new media has come to play an increasingly significant role in communicating information on climate change to the public. Ultimately, there is a need for knowledge-based journalism in communicating climate change and energy alternatives to all segments of the U.S. public, but doing this effectively requires engagement with a broader audience in the debate over how best to address climate change. “Honest brokers” must be referenced in the media as they are best equipped to discuss the issue with citizens of different political identities and cultural worldviews. The success of collective efforts to mitigate and adapt to climate change requires not only scientific consensus but the ability to communicate the science in a way that generates greater consensus among the public.
Climate and Health across Africa
Authors: Zaitchik Benjamin F.
Published: December 2016

Humans have understood the importance of climate to human health since ancient times. In some cases, the connections appear to be obvious: a flood can cause drownings, a drought can lead to crop failure and hunger, and temperature extremes pose a risk of exposure. In other cases, the connections are veiled by complex or unobserved processes, such that the influence of climate on a disease epidemic or a conflict can be difficult to diagnose. In reality, however, all climate impacts on health are mediated by some combination of natural and human dynamics that cause individuals or populations to be vulnerable to the effects of a variable or changing climate.

Understanding and managing negative health impacts of climate is a global challenge. The challenge is greater in regions with high poverty and weak institutions, however, and Africa is a continent where the health burden of climate is particularly acute. Observed climate variability in the modern era has been associated with widespread food insecurity, significant epidemics of infectious disease, and loss of life and livelihoods to climate extremes. Anthropogenic climate change is a further stress that has the potential to increase malnutrition, alter the distribution of diseases, and bring more frequent hydrological and temperature extremes to many regions across the continent.

Skillful early warning systems and informed climate change adaptation strategies have the potential to enhance resilience to short-term climate variability and to buffer against negative impacts of climate change. But effective warnings and projections require both scientific and institutional capacity to address complex processes that are mediated by physical, ecological, and societal systems. Here the state of understanding climate impacts on health in Africa is summarized through a selective review that focuses on food security, infectious disease, and extreme events. The potential to apply scientific understanding to early warning and climate change projection is also considered.
Religious Transitions in Twentieth Century Southeast Asia
Authors: Winzeler Robert L.
Published: December 2016

This is an advance summary of a forthcoming article in the Oxford Research Encyclopedia of Asian History. Please check back later for the full article.

The diverse religions of the peoples of Southeast Asia include indigenous traditions of supernaturally oriented beliefs and practices plus four of the largest world religions: Hinduism, Buddhism, Islam, and Christianity. The main changes that have taken place in religion in 20th-century Southeast Asia include several developments. The first notable change was increased conversion to one or another of the world religions, especially Christianity. The second was national efforts to eliminate or reduce religion in some countries and to shape or control it in others. In addition, popular religion in some instances became more politicized and linked to conflict, especially between Christian and Muslim communities. There were efforts at reform, to modernize religious traditions, or often to bring them into line with orthodoxy.

These religious changes occurred in two phases. The first, involving conversion, had begun in some areas long before, but was furthered and intensified in the 20th century as colonial governments extended control beyond urban areas, to coastal enclaves, lowland agricultural regions, and over interior and mountainous areas, making these more accessible to mission efforts. The second phase of change began in the middle decades of the 20th century as the colonized countries (including all the present-day Southeast Asian nations except Thailand) gained independence and then often attempted to shape religion in various ways. These efforts varied, but the main line of differentiation was between what happened in the socialist regimes, on the one hand, and in the non-socialist ones, on the other. The socialist countries were more inclined than the non-socialist ones to diminish, deemphasize, or control religion, and to block or inhibit missionization. The results can be seen today, where unconverted communities are common or even prevalent in the highland or tribal areas of Vietnam, Laos, and Cambodia, in contrast to such areas in Thailand and—though less can be said about it—Myanmar. Finally, as a result of these changes, over the course of the 20th century and throughout Southeast Asia generally, there has been a reduction in religious diversity, above all as a result of the conversion of people from many different indigenous religious traditions to one or another of the fewer world religions. This is not to say, however, that adherents of Buddhism Christianity, Islam, or Hinduism are necessarily very similar to others of the same world religion.
OCHROCONIS gallopava ENDOPHTHALMITIS SUCCESSFULLY TREATED WITH INTRAVITREAL VORICONAZOLE AND AMPHOTERICIN B
Authors: Kim Esther L. , Patel Sachi R. , George Meena S. , Ameri Hossein
Published: December 2016

Purpose:

Ochroconis gallopava is a darkly pigmented septated fungus that rarely infects humans, almost universally immunocompromised individuals. Only one previous case has been reported of O. gallopava endophthalmitis, in which the patient progressed to a visual acuity of no light perception. The authors currently describe the first successfully treated case of O. gallopava endophthalmitis.

Methods:

A 65-year-old Hispanic woman on chronic immunosuppression after a right lung transplant was admitted to the hospital for O. gallopava respiratory tract infection and was found to have bilateral endogenous endophthalmitis. Examination revealed multiple, cream-colored, chorioretinal lesions in the fundus, including one near the temporal macula in the left eye. There was no diffuse vitritis. Visual acuity was 20/30 in both eyes at presentation but dropped to 20/400 in the right eye and counting fingers at 3 feet in the left eye over the hospital course despite receiving an intravitreal injection of voriconazole in the left eye and concurrent IV amphotericin B, posaconazole, and micafungin. The patient was then treated with multiple simultaneous intravitreal amphotericin B and voriconazole injections bilaterally, as well as IV posaconazole, which was switched to IV voriconazole for improved intraocular penetration.

Results:

The chorioretinal lesions were noted to regress with treatment. Concomitantly, the patient's respiratory status improved, and she was discharged with a visual acuity of 20/40 in the right eye and 20/60 in the left eye. The patient completed a 1-year course of oral voriconazole as an outpatient without signs of recurrent activity. Seventeen months after the initial presentation, the patient had 20/40 vision bilaterally with a residual, white, fibrotic scar at the temporal macula in the left eye.

Conclusion:

This report describes the first successful treatment regimen against O. gallopava endophthalmitis using a combination of intravitreal amphotericin B and voriconazole injections, as well as IV posaconazole and voriconazole, which resulted in an excellent visual outcome.
Behavioural change models for infectious disease transmission: a systematic review (2010–2015)
Authors: Verelst Frederik , Willem Lander , Beutels Philippe
Published: December 2016

We review behavioural change models (BCMs) for infectious disease transmission in humans. Following the Cochrane collaboration guidelines and the PRISMA statement, our systematic search and selection yielded 178 papers covering the period 2010–2015. We observe an increasing trend in published BCMs, frequently coupled to (re)emergence events, and propose a categorization by distinguishing how information translates into preventive actions. Behaviour is usually captured by introducing information as a dynamic parameter (76/178) or by introducing an economic objective function, either with (26/178) or without (37/178) imitation. Approaches using information thresholds (29/178) and exogenous behaviour formation (16/178) are also popular. We further classify according to disease, prevention measure, transmission model (with 81/178 population, 6/178 metapopulation and 91/178 individual-level models) and the way prevention impacts transmission. We highlight the minority (15%) of studies that use any real-life data for parametrization or validation and note that BCMs increasingly use social media data and generally incorporate multiple sources of information (16/178), multiple types of information (17/178) or both (9/178). We conclude that individual-level models are increasingly used and useful to model behaviour changes. Despite recent advancements, we remain concerned that most models are purely theoretical and lack representative data and a validation process.
The emergence of core eudicots: new floral evidence from the earliest Late Cretaceous
Authors: Friis Else Marie , Pedersen Kaj Raunsgaard , Crane Peter R.
Published: December 2016

Eudicots, the most diverse of the three major clades of living angiosperms, are first recognized in the latest Barremian–earliest Aptian. All Early Cretaceous forms appear to be related to species-poor lineages that diverged before the rise of core eudicots, which today comprise more than 70% of angiosperm species. Here, we report the discovery of a well-preserved flower,Caliciflora mauldinensis, from the earliest Late Cretaceous, with unequivocal core eudicot features, including five sepals, five petals and two whorls of stamens borne on the rim of a floral cup containing three free carpels. Pollen is tricolporate. Carpels mature into follicular fruitlets. This character combination suggests a phylogenetic position among rosids, but more specific assignment is precluded by complex patterns of character evolution among the very large number of potentially relevant extant taxa. The whorled floral organization is consistent with ideas that this stable pattern evolved early and was a prerequisite for more integrated patterns of floral architecture that evolved later. However, limited floral synorganization inCalicifloraand all earlier eudicot flowers recognized so far, calls into question hypotheses that substantial diversification of core eudicots had already occurred by the end of the Early Cretaceous.
Specialized proteinine rove beetles shed light on insect–fungal associations in the Cretaceous
Authors: Cai Chenyang , Newton Alfred F. , Thayer Margaret K. , Leschen Richard A. B. , Huang Diying
Published: December 2016

Insects and fungi have a long history of association in shared habitats. Fungus-feeding, or mycophagy, is remarkably widespread in beetles (Coleoptera) and appears to be a primitive feeding habit that preceded feeding on plant tissues. Numerous Mesozoic beetles belonging to extant fungus-associated families are known, but direct fossil evidence elucidating mycophagy in insects has remained elusive. Here, we report a remarkable genus and species,Vetuproteinus cretaceusgen. et sp. nov., belonging to a new tribe (Vetuproteinini trib. nov.) of the extant rove beetle subfamily Proteininae (Staphylinidae) in Mid-Cretaceous Burmese amber. The mouthparts of this beetle have a markedly enlarged protruding galea bearing an apparent spore brush, a specialized structure we infer was used to scrape spores off surfaces and direct them into the mouth, as in multiple modern spore-feeding beetles. Considering the long evolutionary history of Fungi, the Mid-Cretaceous beetles likely fed on ancient Basidiomycota and/or Ascomycota fungi or spore-producing organisms such as slime moulds (Myxomycetes). The discovery of the first Mesozoic proteinine illustrates the antiquity of the subfamily, and suggests that ancestral Proteininae were already diverse and widespread in Pangaea before the supercontinent broke up.
Distance-decay effect in stone tool transport by wild chimpanzees
Authors: Luncz Lydia V. , Proffitt Tomos , Kulik Lars , Haslam Michael , Wittig Roman M.
Published: December 2016

Stone tool transport leaves long-lasting behavioural evidence in the landscape. However, it remains unknown how large-scale patterns of stone distribution emerge through undirected, short-term transport behaviours. One of the longest studied groups of stone-tool-using primates are the chimpanzees of the Taï National Park in Ivory Coast, West Africa. Using hammerstones left behind at chimpanzee
Panda
nut-cracking sites, we tested for a distance-decay effect, in which the weight of material decreases with increasing distance from raw material sources. We found that this effect exists over a range of more than 2 km, despite the fact that observed, short-term tool transport does not appear to involve deliberate movements away from raw material sources. Tools from the millennia-old Noulo site in the Taï forest fit the same pattern. The fact that chimpanzees show both complex short-term behavioural planning, and yet produce a landscape-wide pattern over the long term, raises the question of whether similar processes operate within other stone-tool-using primates, including hominins. Where hominin landscapes have discrete material sources, a distance-decay effect, and increasing use of stone materials away from sources, the Taï chimpanzees provide a relevant analogy for understanding the formation of those landscapes.
Sensory specificity and speciation: a potential neuronal pathway for host fruit odour discrimination in
Rhagoletis pomonella
Authors: Tait Cheyenne , Batra Srishti , Ramaswamy Sree Subha , Feder Jeffrey L. , Olsson Shannon B.
Published: December 2016

Behavioural changes in habitat or mate choice can trigger population divergence, leading to speciation. However, little is known about the neurological bases for such changes.
Rhagoletis pomonella
(Diptera: Tephritidae) is a model for ecological speciation via host plant shifts. Within the past 180 years,
Rhagoletis
flies infesting hawthorn (
Crataegus
spp.) shifted to attack domesticated apple (
Malus pumila
). The two populations differ in their olfactory preferences for apple versus hawthorn fruit. Here, we looked for patterns of sensory organization that may have contributed to this shift by characterizing the morphology, specificity and distribution of olfactory sensory neurons (OSNs) on the antennae of
Rhagoletis
responding to host fruit and non-host volatiles. Of 28 OSN classes identified, two colocalized OSN pairs were found that specifically responded to the major behavioural attractant and antagonist volatiles for each fly population. A reversal in the response of these OSNs to fruit volatiles, either through a switch in receptor expression between these paired neurons or changes in neuronal projections in the brain, could therefore account for the behavioural difference between apple and hawthorn flies. The finding supports the hypothesis that relatively minor changes in olfactory sensory pathways may contribute to rapid host shifting and divergence in
Rhagoletis
.
Comparative tests of the role of dewlap size in
Anolis
lizard speciation
Authors: Ingram Travis , Harrison Alexis , Mahler D. Luke , Castañeda María del Rosario , Glor Richard E. , Herrel Anthony , Stuart Yoel E. , Losos Jonathan B.
Published: December 2016

Phenotypic traits may be linked to speciation in two distinct ways: character values may influence the rate of speciation or diversification in the trait may be associated with speciation events. Traits involved in signal transmission, such as the dewlap of
Anolis
lizards, are often involved in the speciation process. The dewlap is an important visual signal with roles in species recognition and sexual selection, and dewlaps vary among species in relative size as well as colour and pattern. We compile a dataset of relative dewlap size digitized from photographs of 184 anole species from across the genus' geographical range. We use phylogenetic comparative methods to test two hypotheses: that larger dewlaps are associated with higher speciation rates, and that relative dewlap area diversifies according to a speciational model of evolution. We find no evidence of trait-dependent speciation, indicating that larger signals do not enhance any role the dewlap has in promoting speciation. Instead, we find a signal of mixed speciational and gradual trait evolution, with a particularly strong signal of speciational change in the dewlaps of mainland lineages. This indicates that dewlap size diversifies in association with the speciation process, suggesting that divergent selection may play a role in the macroevolution of this signalling trait.
Sex as a strategy against rapidly evolving parasites
Authors: Auld Stuart K. J. R. , Tinkler Shona K. , Tinsley Matthew C.
Published: December 2016

Why is sex ubiquitous when asexual reproduction is much less costly? Sex disrupts coadapted gene complexes; it also causes costs associated with mate finding and the production of males who do not themselves bear offspring. Theory predicts parasites select for host sex, because genetically variable offspring can escape infection from parasites adapted to infect the previous generations. We examine this using a facultative sexual crustacean,
Daphnia magna,
and its sterilizing bacterial parasite,
Pasteuria ramosa
. We obtained sexually and asexually produced offspring from wild-caught hosts and exposed them to contemporary parasites or parasites isolated from the same population one year later. We found rapid parasite adaptation to replicate within asexual but not sexual offspring. Moreover, sexually produced offspring were twice as resistant to infection as asexuals when exposed to parasites that had coevolved alongside their parents (i.e. the year two parasite). This fulfils the requirement that the benefits of sex must be both large and rapid for sex to be favoured by selection.
Online control of prehension predicts performance on a standardised motor assessment test in 8-12 year-old children
Authors: Blanchard Caroline C.V. , McGlashan Hannah L. , French Blandine , Sperring Rachel J. , Petrocochino Bianca , Holmes Nicholas P.
Published: December 2016

Goal-directed hand movements are guided by sensory information and may be adjusted ‘online’, during the movement. If the target of a movement unexpectedly changes position, trajectory corrections can be initiated in as little as 100ms in adults. This rapid visual online control is impaired in children with developmental coordination disorder (DCD), and potentially in other neurodevelopmental conditions. We investigated the visual control of hand movements in children in a ‘centre-out’ double-step reaching and grasping task, and examined how parameters of this visuomotor control co-vary with performance on standardised motor tests often used with typically and atypically developing children. Two groups of children aged 8-12 years were asked to reach and grasp an illuminated central ball on a vertically oriented board. On a proportion of trials, and at movement onset, the illumination switched unpredictably to one of four other balls in a centre-out configuration (left, right, up, or down). When the target moved, all but one of the children were able to correct their movements before reaching the initial target, at least on some trials, but the latencies to initiate these corrections were longer than those typically reported in the adult literature, ranging from 211 to 581 ms. These later corrections may be due to less developed motor skills in children, or to the increased cognitive and biomechanical complexity of switching movements in four directions. In the first group (n=187), reaching and grasping parameters significantly predicted standardised movement scores on the MABC-2, most strongly for the aiming and catching component. In the second group (n=85), these same parameters did not significantly predict scores on the DCDQ-07 parent questionnaire. Our reaching and grasping task provides a sensitive and continuous measure of movement skill that predicts scores on standardized movement tasks used to screen for DCD.
Activity-dependent expression of reporter proteins at dendritic spines for synaptic activity mapping and optogenetic stimulation
Authors: Gobbo Francesco , Marchetti Laura , Alia Claudia , Luin Stefano , Cattaneo Antonino
Published: December 2016

Increasing evidence points to the importance of dendritic spines in the formation and allocation of memories, and alterations of spine number and physiology are associated to memory and cognitive disorders. Synaptic connections and pathways constitute the physical substrate that conveys information in the brain, and different combinations of active synaptic connections are believed to be responsible for the encoding of specific memories. In addition, modifications of the activity of such subsets of synapses are believed to be crucial for memory establishment, but a way to directly test this hypothesis, by selectively controlling the activity of potentiated spines, is currently lagging behind. Therefore it would be important to develop methods to tag active synapses for mapping functionally active connections and to selectively stimulate or interfere with active synapses. Here we introduce an approach to express light-sensitive membrane channels at synapses in an activity-dependent way by means of RNA and protein regulatory sequences. This approach is based on the local expression of reporter proteins, including optogenetic probes, at activated synapses and will allow the mapping of previously active synapses and the re-activation of the neuron only at these sites. This will allow extending the investigation of memory processes beyond the current neuron tagging technologies, whose resolution is limited at the cellular scale. Thus, it will be possible to unveil and recall the synaptic engram out of the global set of synapses.
Non-equilibrium chromosome looping via molecular slip-links
Authors: Brackley C. A. , Johnson J. , Michieletto D. , Morozov A. N. , Nicodemi M. , Cook P. R. , Marenduzzo D.
Published: December 2016

We propose a model for the formation of chromatin loops based on the diffusive sliding of a DNA-bound factor which can dimerise to form a molecular slip-link. Our slip-links mimic the behaviour of cohesin-like molecules, which, along with the CTCF protein, stabilize loops which organize the genome. By combining 3D Brownian dynamics simulations and 1D exactly solvable non-equilibrium models, we show that diffusive sliding is sufficient to account for the strong bias in favour of convergent CTCF-mediated chromosome loops observed experimentally. Importantly, our model does not require any underlying, and energetically costly, motor activity of cohesin. We also find that the diffusive motion of multiple slip-links along chromatin may be rectified by an intriguing ratchet effect that arises if slip-links bind to the chromatin at a preferred "loading site". This emergent collective behaviour is driven by a 1D osmotic pressure which is set up near the loading point, and favours the extrusion of loops which are much larger than the ones formed by single slip-links.
Characterizing the reproductive transcriptomic correlates of acute dehydration in males in the desert-adapted rodent,Peromyscus eremicus
Authors: Kordonowy Lauren , MacManes Matthew
Published: December 2016

The understanding of genomic and physiological mechanisms related to how organisms living in extreme environments survive and reproduce is an outstanding question facing evolutionary and organismal biologists. One interesting example of adaptation is related to the survival of mammals in deserts, where extreme water limitation is common. Research on desert rodent adaptations has focused predominantly on adaptations related to surviving dehydration, while potential reproductive physiology adaptations for acute and chronic dehydration have been relatively neglected. This study aims to explore the reproductive consequences of acute dehydration by utilizing RNAseq data in the desert-specialized cactus mouse(Peromyscus eremicus). Specifically, we exposed 22 male cactus mice to either acute dehydration or control (fully hydrated) treatment conditions, quasimapped testes-derived reads to a cactus mouse testes transcriptome, and then evaluated patterns of differential transcript and gene expression. Following statistical evaluation with multiple analytical pipelines, nine genes were consistently differentially expressed between the hydrated and dehydrated mice. We hypothesized that male cactus mice would exhibit minimal reproductive responses to dehydration; therefore, this low number of differentially expressed genes between treatments aligns with current perceptions of this species' extreme desert specialization. However, these differentially expressed genes include Insulin-like 3 (Insl3), a regulator of male fertility and testes descent, as well as the solute carriers Slc45a3 and Slc38a5, which are membrane transport proteins that may facilitate osmoregulation. Together, these results suggest that in male cactus mice, acute dehydration may be linked to reproductive modulation via Insl3, but not through gene expression differences in the subset of other a priori tested reproductive hormones. Although water availability is a reproductive cue in desert-rodents exposed to chronic drought, potential reproductive modification via Insl3 in response to acute water-limitation is a result which is unexpected in an animal capable of surviving and successfully reproducing year-round without available external water sources. Indeed, this work highlights the critical need for integrative research that examines every facet of organismal adaptation, particularly in light of global climate change, which is predicted, amongst other things, to increase climate variability, thereby exposing desert animals more frequently to the acute drought conditions explored here.
Radiation attenuation by single-crystal diamond windows
Authors: Guthrie M. , Pruteanu C. G. , Donnelly M.-E. , Molaison J. J. , dos Santos A. M. , Loveday J. S. , Boehler R. , Tulk C. A.
Published: December 2016

As artificial diamond becomes more cost effective it is likely to see increasing use as a window for sample environment equipment used in diffraction experiments. Such windows are particularly useful as they exhibit exceptional mechanical properties in addition to being highly transparent to both X-ray and neutron radiation. A key application is in high-pressure studies, where diamond anvil cells (DACs) are used to access extreme sample conditions. However, despite their utility, an important consideration when using single-crystal diamond windows is their interaction with the incident beam. In particular, the Bragg condition will be satisfied for specific angles and wavelengths, leading to the appearance of diamond Bragg spots on the diffraction detectors but also, unavoidably, to loss of transmitted intensity of the beam that interacts with the sample. This effect can be particularly significant for energy-dispersive measurements, for example, in time-of-flight neutron diffraction work using DACs. This article presents a semi-empirical approach that can be used to correct for this effect, which is a prerequisite for the accurate determination of diffraction intensities.
Crystal structure of bis[cis-(1,4,8,11-tetraazacyclotetradecane-κ4N)bis(thiocyanato-κN)chromium(III)] dichromate monohydrate from synchrotron X-ray diffraction data
Authors: Moon Dohyun , Takase Masahiro , Akitsu Takashiro , Choi Jong-Ha
Published: December 2016

The structure of the complex salt,cis-[Cr(NCS)2(cyclam)]2[Cr2O7]·H2O (cyclam = 1,4,8,11-tetraazacyclotetradecane, C10H24N4), has been determined from synchrotron data. The asymmetric unit comprises of one [Cr(NCS)2(cyclam)]+cation, one half of a Cr2O72−anion (completed by inversion symmetry) and one half of a water molecule (completed by twofold rotation symmetry). The CrIIIion is coordinated by the four cyclam N atoms and by two N atoms ofcis-arranged thiocyanate anions, displaying a distorted octahedral coordination sphere. The Cr—N(cyclam) bond lengths are in the range 2.080 (2) to 2.097 (2) Å while the average Cr—N(NCS) bond length is 1.985 (4) Å. The macrocyclic cyclam moiety adopts thecis-V conformation. The bridging O atom of the dichromate anion is disordered around an inversion centre, leading to a bending of the Cr—O—Cr bridging angle [157.7 (3)°]; the anion has a staggered conformation. The crystal structure is stabilized by intermolecular hydrogen bonds involving the cyclam N—H groups and water O—H groups as donor groups, and the O atoms of the Cr2O72−anion and water molecules as acceptor groups, giving rise to a three-dimensional network.
Crystal structure of human chondroadherin: solving a difficult molecular-replacement problem usingde novomodels
Authors: Rämisch Sebastian , Pramhed Anna , Tillgren Viveka , Aspberg Anders , Logan Derek T.
Published: December 2016

Chondroadherin (CHAD) is a cartilage matrix protein that mediates the adhesion of isolated chondrocytes. Its protein core is composed of 11 leucine-rich repeats (LRR) flanked by cysteine-rich domains. CHAD makes important interactions with collagen as well as with cell-surface heparin sulfate proteoglycans and α2β1integrins. The integrin-binding site is located in a region of hitherto unknown structure at the C-terminal end of CHAD. Peptides based on the C-terminal human CHAD (hCHAD) sequence have shown therapeutic potential for treating osteoporosis. This article describes a still-unconventional structure solution by phasing withde novomodels, the first of a β-rich protein. Structure determination of hCHAD using traditional, though nonsystematic, molecular replacement was unsuccessful in the hands of the authors, possibly owing to a combination of low sequence identity to other LRR proteins, four copies in the asymmetric unit and weak translational pseudosymmetry. However, it was possible to solve the structure by generating a large number ofde novomodels for the central LRR domain usingRosettaand multiple parallel molecular-replacement attempts usingAMPLE. The hCHAD structure reveals an ordered C-terminal domain belonging to the LRRCT fold, with the integrin-binding motif (WLEAK) being part of a regular α-helix, and suggests ways in which experimental therapeutic peptides can be improved. The crystal structure itself and docking simulations further support that hCHAD dimers form in a similar manner to other matrix LRR proteins.
3-Methoxy-2-p-tolyl-4H-chromen-4-one
Authors: Koh Dongsoo
Published: December 2016

In the title compound, C17H14O3, the methyl-substituted benzene ring is twisted relative to the 4H-chromenon skeleton by 51.5 (2)°. The C atom of the methoxy group of the 4H-chromenon unit is displaced from the ring plane by 1.225 (2) Å. In the crystal, C—H—O interactions connect the molecules into (001) sheets.
Re-thinking induction in practice: profession, peer group and organization in contention
Authors: Gherardi Silvia , Perrotta Manuela
Published: December 2016

Purpose

The purpose of this paper is to develop an interpretative framework of induction as a social practice to examine the ecology of the human and non-human actors involved in the production of induction as a social effect.

Design/methodology/approach

Three case studies are conducted in different types of organizations (private, public and network) to analyse the relation between the induction process and the actors that influence it.

Findings

Three different models of induction are described: in a professional bureaucracy, socialization precedes selections and the key actor is the profession; in a small private organization, induction is almost exclusively managed by the peer group in the form of seduction by the profession; in a large network of organizations, induction is explicitly managed by the organization and becomes a means to transmit the organizational culture.

Research limitations/implications

In the description of the empirical data, it is shown how an individual undergoes induction into the organization when he/she undergoes seduction (by the profession). Nevertheless, the models could be improved by the study of a larger sample of organizations.

Originality/value

This paper shows that induction is not the effect of solely the encounter between individual and organization, because two other agents are involved in the process, namely the profession and the peer group.
Conceptualising public-private partnerships
Authors: Mouraviev Nikolai , Kakabadse Nada K.
Published: December 2016

Purpose

The purpose of this paper is to survey various meanings attached to a public–private partnership (PPP) and related aspects in Western literature and to identify commonalities and differences between them. Additionally, the article intends to critically assess conflicting and overlapping views on contractual and institutional PPPs, their forms and models and to draw insights for transitional economies.

Design/methodology/approach

The article contrasts and compares views on PPP meanings, forms and models within Western PPP literature and also draws comparisons with understanding of partnership aspects in the Russian language sources. The paper examines theories underpinning PPPs, builds connections to PPP advantages and drawbacks and provides critical assessment of net benefits that PPPs may bring along to the society.

Findings

The article concludes that future PPP research in transitional countries such as Kazakhstan and Russia, particularly in the area of organisational and power arrangements in partnerships, may delineate new concepts such as government as a guarantor of a PPP project, social significance of a PPP project and risk management in a country’s contextual environment.

Originality/value

Research in the field of PPPs in transitional countries such as Russia and Kazakhstan is in its infancy. The paper intends to contribute to the body of knowledge about PPPs by providing detailed account and categorisation of their principal meanings, forms, models and underpinning theories and by drawing insights for future research in transitional countries.