bluuebunny/crossref_metadata_2025_split huggingface dataset:
Economic reforms, determinants and stability of dividends in a dynamic setting
Authors: Subhash Kamat Manoj , Kamat Manasvi M. 
Published: January 2013

PurposeThis study aims to find whether the Indian private corporate sector follow stable cash dividend policies, whether dividends smoothen earnings, estimate the implicit target dividend ratio, and examine the determinants along with speed of adjustment of dividends towards a long run target ratio.Design/methodology/approachThe study uses the instrumental variable (IV) approach for dynamic panel data for 1971‐2010 periods controlling for economic reforms. The GMM‐in‐levels model, GMM‐in‐first‐differences and GMM‐in‐systems are alternatively estimated to include other lag structures.FindingsIn the post‐reform period lower dividends are consistent with rapid growth in the economic environment and the tendency to smoothen dividends has considerably decreased over time. The estimated model suggests dividends substitute for less opportunity for internal growth and increased general likening to relatively retain their earnings and finance their growth, unlike the past.Research limitations/implicationsLimitation to capture substitution, ownership and self selection effects stems up from data as the Annual Studies RBI does not include such variables, does not capture qualitative data and disallows identification of the firm.Practical implicationsThe paper documents long run trends and inter‐temporal dividend patterns controlling economic reforms for a relatively larger number of public limited firms nearing four decades for an emerging economy.Originality/valueThis is a first attempt to take a holistic view of dividend using rich set of unexplored dynamic panel data on Indian firms controlling for reforms using contemporary econometric models and analyzes issues relating determinants, smoothening and stability of the corporate dividend structure.
Intra‐ and interpopulational variation in the ability of a solitary bee species to develop on non‐host pollen: implications for host range expansion
Authors: Haider Mare , Dorn Silvia , Müller Andreas 
Published: January 2013

Summary

Pollen host choice in bees is in many cases highly conserved, which might partly be due to physiological limitations of bee larvae to digest non‐host pollen. These limitations need to be overcome in order to incorporate new pollen hosts; however, the mechanisms underlying such host expansion are poorly understood.
In this study, we examined intra‐ and interpopulational variation in the ability of larvae of the solitary bee species Osmia cornuta (Megachilidae) to develop on a non‐host pollen diet of Ranunculus acris (Ranunculaceae) by comparing larval performance within and between five geographically distant European populations.
The majority of bee larvae from all tested populations died when reared on the Ranunculus pollen diet. Between 10% and 43·5% of all larvae per population reached the cocoon stage, and 48% of these emerged as viable adults from the cocoons, indicating that the physiological ability to cope with the unfavourable properties of Ranunculus pollen exists in each population.
The bee larvae of one population exhibited significantly reduced survival on the Ranunculus pollen diet compared with three of the four other populations.
Although bees that successfully developed on the Ranunculus pollen diet showed a distinctly prolonged development time, exhibited higher mortality during diapause and reached a considerably lower adult weight compared with individuals fed the control pollen diet, several of the Ranunculus fed individuals were able to reproduce and to sire viable offspring.
This study provides the first evidence for both intra‐ and interpopulational variation in the physiological ability of solitary bees to digest non‐host pollen. This variation might enable host expansion and subsequent host shifts in response to natural selection.
The marine controlled source electromagnetic response of a steel borehole casing: applications for the NEPTUNE Canada gas hydrate observatory
Authors: Swidinsky Andrei , Edwards R. Nigel , Jegen Marion 
Published: January 2013

ABSTRACTGas hydrates are a potential energy resource, a possible factor in climate change and an exploration geohazard. The University of Toronto has deployed a permanent seafloor time‐domain controlled source electromagnetic (CSEM) system offshore Vancouver Island, within the framework of the NEPTUNE Canada underwater cabled observatory. Hydrates are known to be present in the area and due to their electrically resistive nature can be monitored by 5 permanent electric field receivers. However, two cased boreholes may be drilled near the CSEM site in the near future. To understand any potential distortions of the electric fields due to the metal, we model the marine electromagnetic response of a conductive steel borehole casing. First, we consider the commonly used canonical model consisting of a 100 Ωm, 100 m thick resistive hydrocarbon layer embedded at a depth of 1000 m in a 1 Ωm conductive host medium, with the addition of a typical steel production casing extending from the seafloor to the resistive zone. Results show that in both the frequency and time domains the distortion produced by the casing occurs at smaller transmitter‐receiver offsets than the offsets required to detect the resistive layer. Second, we consider the experimentally determined model of the offshore Vancouver Island hydrate zone, consisting of a 5.5 Ωm, 36 m thick hydrate layer overlying a 0.7 Ωm sedimentary half‐space, with the addition of two borehole casings extending 300 m into the seafloor. In this case, results show that the distortion produced by casings located within a 100 m safety zone of the CSEM system will be measured at 4 of the 5 receivers. We conclude that the boreholes must be positioned at least 200 m away from the CSEM array so as to minimize the effects of the casings.
Food production vs. biodiversity: comparing organic and conventional agriculture
Authors: Gabriel Doreen , Sait Steven M. , Kunin William E. , Benton Tim G. 
Published: January 2013

Summary

A substantial proportion of the global land surface is used for agricultural production. Agricultural land serves multiple societal purposes; it provides food, fuel and fibre and also acts as habitat for organisms and supports the services they provide. Biodiversity conservation and food production need to be balanced: production needs to be sustainable, while conservation cannot be totally at the expense of crop yield.
To identify the benefits (in terms of biodiversity conservation) and costs (in terms of reduction in yields) of agricultural management, we examined the relationship between crop yield and abundance and species density of important taxa in winter cereal fields on both organic and conventional farms in lowland England.
Of eight species groups examined, five (farmland plants, bumblebees, butterflies, solitary bees and epigeal arthropods) were negatively associated with crop yield, but the shape of this relationship varied between taxa. It was linear for the abundance of bumblebees and species density of butterflies, concave up for the abundance of epigeal arthropods and butterflies and concave down for species density of plants and bumblebees.
Grain production per unit area was 54% lower in organic compared with conventional fields. When controlling for yield, diversity of bumblebees, butterflies, hoverflies and epigeal arthropods did not differ between farming systems, indicating that observed differences in biodiversity between organic and conventional fields are explained by lower yields in organic fields and not by different management practices per se. Only percentage cover and species density of plants were increased by organic field management after controlling for yield. The abundance of solitary wild bees and hoverflies was increased in landscapes with high amount of organic land.
Synthesis and applications. Our results indicate that considerable gains in biodiversity require roughly proportionate reductions in yield in highly productive agricultural systems. They suggest that conservation efforts may be more cost effective in low‐productivity agricultural systems or on non‐agricultural land. In less productive agricultural landscapes, biodiversity benefit can be gained by concentrating organic farms into hotspots without a commensurate reduction in yield.
Laparoscopic lymphocele fenestration in gynaecological cancer patients after retroperitoneal lymph node dissection as a first‐line treatment option
Authors: Radosa MP , Diebolder H , Camara O , Mothes A , Anschuetz J , Runnebaum IB 
Published: January 2013

ObjectiveTo evaluate laparoscopic lymphocele fenestration (LLF) as a first‐line treatment in gynaecological cancer patients with a history of retroperitoneal lymph node dissection (LND).DesignRetrospective cohort study.SettingA tertiary referral centre.PopulationPatients who underwent LLF between January 2001 and December 2010 for a symptomatic lymphocele following retroperitoneal LND.MethodsSurgical outcomes of 102 patients who underwent LLF at our hospital between January 2001 and December 2010 were analysed. Patients were identified using hospital database search software, and hand‐written and electronic charts were reviewed.Main outcome measuresOutcomes included operating time, blood loss, conversion rate, intra‐ and postoperative complication rates, hospital stay and relapse rate.ResultsA total of 132 lymphoceles were fenestrated in 102 patients. The mean duration of surgery was 115.6 minutes and the average intraoperative blood loss per patient was 146 ml. The overall conversion rate to laparotomy was 7.8%. Intra‐ and postoperative complication rates were estimated at 9.8 and 5.9%, respectively. The rate of intraoperative and postoperative complications was significantly higher in patients after pelvic plus paraaortic LND (23.8%), compared with those after pelvic LND only (3.6%; P > 0.01). The mean follow‐up time was 60.4 months and a total of seven symptomatic recurrences of lymphoceles were observed (a recurrence rate of 6.9%).ConclusionsFor the treatment of symptomatic lymphoceles, LLF has previously been established as an efficient first‐line treatment option in a post‐transplant context. Our data suggest that these favourable results for LLF may be transferable to gynaecological cancer patients.
Outcome of severe placental insufficiency with abnormal umbilical artery Doppler prior to fetal viability
Authors: Simonazzi G , Curti A , Cattani L , Rizzo N , Pilu G 
Published: January 2013

ObjectiveTo evaluate the outcome of pregnancies complicated by placental insufficiency and abnormal umbilical artery Doppler prior to viability.DesignA retrospective cohort study.SettingItaly.PopulationSingleton pregnancies with fetal growth restriction and absence of end‐diastolic velocities (AEDVs) in the umbilical arteries prior to 24 weeks.MethodsA retrospective cohort study of singleton pregnancies with fetal growth restriction and AEDVs in the umbilical arteries prior to 24 weeks.Main outcome measuresFetal growth restriction and AEDVs in the umbilical arteries prior to 24 weeks.ResultsOf 16 fetuses first seen at 20–23 weeks, only 12 survived and one of these developed cerebral palsy. Severe hypertensive disorders occurred in three mothers. In four women, the Doppler waveforms progressively improved and developed a normal pulsatility. These fetuses had a better outcome than those that had persistent alterations: they were delivered later (34 versus 28 weeks), had a larger birthweight (1598 versus 630 g) and developed fewer complications.ConclusionsPlacental insufficiency with AEDV in the umbilical arteries prior to fetal viability is associated with a high probability of perinatal death and neonatal complications. However, progressive amelioration of Doppler indices occurs in a subset of women, and these fetuses have a much better outcome.
Diapause development in early and late emerging phenotypes of Delia floralis
Authors: Johansen Tor J. , Meadow Richard 
Published: January 2013

AbstractThe turnip fly, Delia floralis Fallén (Diptera: Anthomyiidae) is an important insect pest of brassica vegetable crops in the holarctic region. Different populations have strongly varying temperature requirements for fly emergence, a challenge for accurate prediction of activity. This study focused on diapause development in one early and one late emerging phenotype. The physiological state after various treatments was deduced from emergence data. Our results showed a slow diapause progression at chilling conditions for both populations and diapause ended about 7 months after pupae were formed for the early population. For the late population held at 4°C diapause did not end, no matter how long the duration of chilling. These pupae required a period with elevated temperatures above 6°C to continue development. At constant non‐chilling conditions (18°C) from the time pupae were formed both populations completed diapause most rapidly. These results indicate that chilling delayed, rather than accelerated development and was not a prerequisite for diapause development. For post‐diapause, results indicated a linear relationship between rate of development and temperature within the range of 6–18°C and a theoretical base temperature for development of about 2°C for both populations. In conclusion, D. floralis pupae are in diapause throughout a long winter period, and delayed emergence of the late population appears to be caused by prolonged diapause regulated by a developmental temperature threshold. The study has added information on the biology of turnip fly populations, a prerequisite for improved pest control.
Ion Torrent‐based transcriptional assessment of a Corynebacterium pseudotuberculosis equi strain reveals denaturing high‐performance liquid chromatography a promising rRNA depletion method
Authors: Castro Thiago L. P. , Seyffert Nubia , Ramos Rommel T. J. , Barbosa Silvanira , Carvalho Rodrigo D. O. , Pinto Anne Cybelle , Carneiro Adriana Ribeiro , Silva Wanderson Marques , Pacheco Luis G. C. , Downson Christopher , Schneider Maria P. C. , Miyoshi Anderson , Azevedo Vasco , Silva Artur 
Published: January 2013

SummaryCorynebacterium pseudotuberculosis equi is a Gram‐positive pathogenic bacterium which affects a variety of hosts. Besides the great economic losses it causes to horse‐breeders, this organism is also known to be an important infectious agent to cattle and buffaloes. As an outcome of the efforts in characterizing the molecular basis of its virulence, several complete genome sequences were made available in recent years, enabling the large‐scale assessment of genes throughout distinct isolates. Meanwhile, the RNA‐seq stood out as the technology of choice for comprehensive transcriptome studies, which may bring valuable information regarding active genomic regions, despite of the still impeditive associated costs. In an attempt to increase the use of generated reads per instrument run, by effectively eliminating unwanted rRNAs from total RNA samples without relying on any commercially available kits, we applied denaturing high‐performance liquid chromatography (DHPLC) as an alternative method to assess the transcriptional profile of C. pseudotuberculosis. We have found that the DHPLC depletion method, allied to Ion Torrent sequencing, allows mapping of transcripts in a comprehensive way and identifying novel transcripts when a de novo approach is used. These data encourage us to use DHPLC in future transcriptional evaluations in C. pseudotuberculosis.
Carbon Isotopic Evolution of the Late Ediacaran Gaojiashan Biota on the Northern Yangtze Platform, South China
Authors: Qingjun GUO , Yinan DENG , Xinglian YANG 
Published: January 2013

Abstract:Metazoan fossils in the Gaojiashan Biota are famous for being well preserved and may provide new insights into the early evolution and skeletonization of Metazoans. We are studying the isotopic compositions of organic and carbonate carbon from a sequence of sedimentary rocks at the Gaojiashan section, northern Yangtze Platform, Shaanxi Province of China. Organic carbon isotope values display a range between −30.8‰ and −24.7‰ with clear stratigraphic variations. Carbonate carbon isotope data vary between 0.1‰ and +6‰. Positive δ13C values from sediments with Gaojiashan biota reflect temporal variations in carbon turnover, i.e. an increasing in photosynthetic carbon fixation followed by an increasing subsequent fractional organic carbon burial, and that related to bio‐radiation such as increasing algae, bacteria, and original creatures productivity in biomass. These secular variations are interpreted to reflect perturbations of the regional carbon cycle, specifically changes in the fractional burial of organic carbon, and discuss the relationship between Gaojiashan biota and paleoenvrionmental variation.
Helium, Argon and Carbon Isotopic Compositions of Spring Gases in the Hainan Island, China
Authors: Sheng XU , Guodong ZHENG , Yongchang XU 
Published: January 2013

Abstract:Chemical and isotopic compositions have been measured for N2‐He‐rich bubbling gases discharging from hot springs in the Hainan Island, Southern China. Observed 3He/4He ratios (0.1–1.3 RA) indicate the occurrence of a mantle component throughout the island, which has been highly diluted by a crustal radiogenic 4He component. The occurrence of mantle‐derived helium is high in the northern island (12%–16% of total He) and gradually decreases towards southern coast (l%–3% of total He). Such a distribution pattern is most likely controlled by the Pleocene‐Quaternary volcanic activities in the northern island and groundwater circulation along the deep major faults. The 40Ar/36Ar and N2/Ar ratios suggest that N2 and Ar of the hot spring gases are mostly meteoric. Although δ13C values of CO2 (–20‰ to −27‰) with low concentrations are consistent with the biogenic origin, the combination of 3He/4He and δ13CCO2 suggests a two end‐member mixing of mantle and crustal components with CO2/3He ratios of 2×109 and 8×1011, respectively. However, the low CO2/3He ratios (1–22×106) can not be ascribed in terms of the simple mixing but has to be explained by the addition of radiogenic 4He and loss of CO2 by calcite precipitation in the hydrothermal system, which is most likely controlled by the degree of gas‐water‐rock interaction.
The depositional Environment at Shuidonggou Locality 2 in Northwest China at ∼72–18 kaBP
Authors: Decheng LIU , Xing GAO , Enfa LIU , Shuwen PEI , Fuyou CHEN , Shuqin ZHANG 
Published: January 2013

Abstract:Shuidonggou site has abundant Paleolithic remains of Late Pleistocene deposition. Studying the evolution of depositional environments is essential to the comprehensive understanding of the living conditions of ancient populations. To reconstruct the depositional environment at Shuidonggou, we carried out archaeological excavations and collected systematic deposition samples at the key position of Shuidonggou Locality 2 for grain size analysis and sporopollen statistics. The environmental evolution around the Shuidonggou site generally underwent four stages at ∼72–18 kaBP. During the first stage (∼72–41 kaBP), the river developed with gravel and sand stratums. During the second stage (41∼34 kaBP), a swamp with numerous aquatic plants formed. In the third stage (34–29 kaBP), site formation was characterized by shallow lake depositional conditions; the climate was relatively warm and humid. The marginal bank depositional conditions deteriorated during the fourth stage (29–18 kaBP), and the site underwent several dry events; the climate also became drier and colder.
Dismantling the Mantel tests
Authors: Guillot Gilles , Rousset François 
Published: January 2013

Summary

The simple and partial Mantel tests are routinely used in many areas of evolutionary biology to assess the significance of the association between two or more matrices of distances relative to the same pairs of individuals or demes. Partial Mantel tests rather than simple Mantel tests are widely used to assess the relationship between two variables displaying some form of structure.
We show that contrary to a widely shared belief, partial Mantel tests are not valid in this case, and their bias remains close to that of the simple Mantel test.
We confirm that strong biases are expected under a sampling design and spatial correlation parameter drawn from an actual study.
The Mantel tests should not be used in case autocorrelation is suspected in both variables compared under the null hypothesis. We outline alternative strategies. The R code used for our computer simulations is distributed as supporting material.
Tracking rodent‐dispersed large seeds with Passive Integrated Transponder (PIT) tags
Authors: Suselbeek L. , Jansen P. A. , Prins H. H. T. , Steele M. A. 
Published: January 2013

Summary

Seed dispersal, a critical phase in the life history of many plants, is poorly understood due to the difficulty of tracking and monitoring dispersing seeds until they reach their ultimate fate. Scatter‐hoarding rodents play a substantial part in the seed dispersal process of many plant species, however, existing tracking methods do not allow seed monitoring without risk of influencing the hoarding process and seed fate.

Here, we describe and test the use of Passive Integrated Transponders (PIT) tags inserted into seeds for the tracking and monitoring of large seeds dispersed by rodents. Unlike other tagging methods, PIT tagging combines the advantages of leaving no external cues and being readable without disturbance of caches. Rodents cannot remove these tags.

We evaluated the performance of PIT tagging through a series of trials with Quercus acorns dispersed by rodents, both in North America and in Europe, with equipment from different manufacturers. We quantified effects of tagging on seed removal and caching, cache pilferage and seed germination, by comparison between PIT‐tagged and untagged acorns. We evaluated the detectability of buried tags to researchers.

Minimal effects of PIT tagging on seed removal, caching, pilferage and germination were found. Buried PIT tags were retrieved with high reliability by naïve researchers, even at burial depths up to 30 cm. Identification codes could be read even when multiple tags were buried at a single location, as in larder hoarding.

The method was successfully applied in two field studies of dispersal of Quercus palustris and Q. rubra acorns by Eastern grey squirrels Sciurus carolinensis in North America, and Q. robur acorns by Wood mice Apodemus sylvaticus in the Netherlands. The proportion of seeds recovered was comparable to that in studies using traditional thread tags.

We conclude that PIT tagging is a particularly suitable method for tracking and monitoring of seeds dispersed by scatter‐hoarding rodents. PIT tagging solves most of the main problems generally encountered when following the fate of rodent‐dispersed seeds over time.