This article uses longitudinal data to estimate the shortand medium-term economic effects of divorce in the USA, the UK, Switzerland, Korea, Germany and Australia during the first decade of the 21st ...century. Based on the data collected during the 2000s, in all of the countries studied, divorce had, on average, negative effects on the equivalised household incomes of women. However, the extent and duration of the negative effects of divorce differed markedly between countries. In all of the countries, the effects of divorce on the equivalised household income of men were smaller than for women. Although, using the available data, it is not possible to definitely explain the differences between countries, the analysis presented in this article has demonstrated that the average economic effects of divorce, particularly for women, are heavily influenced by the social security system, the labour market, family models and the family law system of each country. While the social security system and institutional arrangements such as child support and spousal maintenance do influence women's post-divorce economic outcomes, what is most important in explaining cross-country differences is women's labour market earnings and the extent to which re-partnering occurs.
Red deer (Cervus elaphus) have played a key role in human societies throughout history, with important cultural significance and as a source of food and materials. This relationship can be traced ...back to the earliest human cultures and continues to the present day. Humans are thought to be responsible for the movement of a considerable number of deer throughout history, although the majority of these movements are poorly described or understood. Studying such translocations allows us to better understand ancient human–wildlife interactions, and in the case of island colonizations, informs us about ancient human maritime practices. This study uses DNA sequences to characterise red deer genetic diversity across the Scottish islands (Inner and Outer Hebrides and Orkney) and mainland using ancient deer samples, and attempts to infer historical colonization events. We show that deer from the Outer Hebrides and Orkney are unlikely to have originated from mainland Scotland, implying that humans introduced red deer from a greater distance. Our results are also inconsistent with an origin from Ireland or Norway, suggesting long-distance maritime travel by Neolithic people to the outer Scottish Isles from an unknown source. Common haplotypes and low genetic differentiation between the Outer Hebrides and Orkney imply common ancestry and/or gene flow across these islands. Close genetic proximity between the Inner Hebrides and Ireland, however, corroborates previous studies identifying mainland Britain as a source for red deer introductions into Ireland. This study provides important information on the processes that led to the current distribution of the largest surviving indigenous land mammal in the British Isles.
High levels of reactive oxygen species (ROS) contribute to muscle cell death in aging and disuse. We have previously found that resveratrol can reduce oxidative stress in response to aging and ...hindlimb unloading in rodents in vivo, but it was not known if resveratrol would protect muscle stem cells during repair or regeneration when oxidative stress is high. To test the protective role of resveratrol on muscle stem cells directly, we treated the C2C12 mouse myoblast cell line with moderate (100 μM) or very high (1 mM) levels of H2O2 in the presence or absence of resveratrol. The p21 promoter activity declined in myoblasts in response to high ROS, and this was accompanied a greater nuclear to cytoplasmic translocation of p21 in a dose-dependent matter in myoblasts as compared to myotubes. Apoptosis, as indicated by TdT-mediated dUTP nick-end labeling, was greater in C2C12 myoblasts as compared to myotubes (P<.05) after treatment with H2O2. Caspase-9, -8 and -3 activities were elevated significantly (P<.05) in myoblasts treated with H2O2. Myoblasts were more susceptible to ROS-induced oxidative stress than myotubes. We treated C2C12 myoblasts with 50 μM of resveratrol for periods up to 48 h to determine if myoblasts could be rescued from high-ROS-induced apoptosis by resveratrol. Resveratrol reduced the apoptotic index and significantly reduced the ROS-induced caspase-9, -8 and -3 activity in myoblasts. Furthermore, Bcl-2 and the Bax/Bcl-2 ratio were partially rescued in myoblasts by resveratrol treatment. Similarly, muscle stem cells isolated from mouse skeletal muscles showed reduced Sirt1 protein abundance with H2O2 treatment, but this could be reversed by resveratrol. Reduced apoptotic susceptibility in myoblasts as compared to myotubes to ROS is regulated, at least in part, by enhanced p21 promoter activity and nuclear p21 location in myotubes. Resveratrol confers further protection against ROS by improving Sirt1 levels and increasing antioxidant production, which reduces mitochondrial associated apoptotic signaling, and cell death in myoblasts.
The use of ecological replacements (analogue species to replace extinct taxa) to restore ecosystem functioning is a promising conservation tool. However, this approach is controversial, in part due ...to a paucity of data on interactions between analogue species and established taxa in the ecosystem.
We conducted ecological surveys, comprehensively DNA barcoded an ecosystem's flora and inferred the diet of the introduced Aldabra giant tortoise, acting as an ecological replacement, to understand how it might have modified island plant communities on a Mauritian islet. Through further dietary analyses, we investigated consequential effects on the threatened endemic Telfair's skink.
Dietary overlap between tortoises and skinks was greater than expected by chance. However, there was a negative correlation between tortoise and skink preferences in herbivory and minimal overlap in the plants most frequently consumed by the reptiles.
Changes in the plant community associated with 7 years of tortoise grazing were characterised by a decrease in the percentage cover of native herbs and creepers, and an increase in the cover of an invasive herb when compared to areas without tortoises. However, tortoise dietary preferences themselves did not directly drive changes in the plant community.
Tortoises successfully dispersed the seeds of an endemic palm, which in time may increase the extent of unique palm‐rich habitat. We found no evidence that tortoises have increased the extent of plant species hypothesised to be part of a lost Mauritian tortoise grazed community.
Synthesis and applications. Due to a negative correlation in tortoise and skink dietary preferences and minimal overlap in the most frequently consumed taxa, the presence of tortoises is unlikely to have detrimental impacts on Telfair's skinks. Tortoise presence is likely to be beneficial to skinks in the long term by increasing the extent of palm‐rich habitat. Although tortoises are likely to play a role in controlling invasive plants, they are not a panacea for this challenge. After 7 years, tortoises have not resurrected a lost tortoise grazed community that we hypothesise might have existed in limited areas on the islet, indicating that further interventions may be required to restore this plant community.
Résumé
L'utilisation de remplacements écologiques (espèces analogues pour remplacer les taxons éteints) pour restaurer le fonctionnement d'un écosystème est un outil de conservation prometteur. Cependant, cette approche est controversée, en partie à cause d'un manque de données sur les interactions entre les espèces analogues et les taxons présents dans l'écosystème.
Nous avons mené des études écologiques, codé l’ADN de la flore d'un écosystème et déduit le régime alimentaire de la tortue géante d'Aldabra, espèce introduite agissant comme un remplacement écologique, pour comprendre comment elle aurait potentiellement modifié les communautés végétales insulaires sur un îlot mauricien. Grâce à d'autres analyses alimentaires, nous avons étudié les effets résultants sur le scinque de Telfair, une espèce endémique menacée.
Le chevauchement entre l'alimentation des tortues et les scinques était plus important que prévu. Cependant, il y avait une corrélation négative entre les préférences des tortues et des scinques au niveau de l'herbivorie et un chevauchement minime pour les plantes les plus fréquemment consommées par ces reptiles.
Les changements dans la communauté végétale associés à sept années de broutage des tortues ont été caractérisés par une diminution du pourcentage de couverture d'herbes et de plantes grimpantes indigènes, et une augmentation de la couverture d'une herbe envahissante par rapport aux zones sans tortues. Cependant, les préférences alimentaires des tortues elles‐mêmes n'ont pas directement entraîné de changements dans la communauté végétale.
Les tortues ont réussi à disperser les graines d'un palmier endémique, ce qui, avec le temps, pourrait augmenter l'étendue de l'habitat riche en palmiers. Nous n'avons trouvé aucune preuve que les tortues ont augmenté l'étendue des espèces végétales supposées faire partie d'une communauté végétale disparue qui existait dû au broutage des tortues mauriciennes.
Synthèse et applications. En raison d'une corrélation négative dans les préférences alimentaires des tortues et des scinques et d'un chevauchement minimal dans les taxons les plus fréquemment consommés, il est peu probable que la présence de tortues ait des effets néfastes sur les scinques de Telfair. La présence de tortues est susceptible d'être bénéfique pour les scinques à long terme en augmentant l'étendue de l'habitat riche en palmiers. Bien que les tortues soient susceptibles de jouer un rôle dans le contrôle des plantes envahissantes, elles ne sont pas une panacée pour ce défi. Après sept ans, les tortues n'ont pas ressuscité la communauté végétale disparue qui existait dû au broutage des tortues endémique qui, selon nous, aurait pu exister dans des zones limitées de l'îlot, ce qui indique que d'autres interventions pourraient être nécessaires pour restaurer cette communauté végétale.
Due to a negative correlation in tortoise and skink dietary preferences and minimal overlap in the most frequently consumed taxa, the presence of tortoises is unlikely to have detrimental impacts on Telfair's skinks. Tortoise presence is likely to be beneficial to skinks in the long term by increasing the extent of palm‐rich habitat. Although tortoises are likely to play a role in controlling invasive plants, they are not a panacea for this challenge. After 7 years, tortoises have not resurrected a lost tortoise grazed community that we hypothesise might have existed in limited areas on the islet, indicating that further interventions may be required to restore this plant community.
Background
Sirtuin 1 (SIRT1) is a NAD+ sensitive deacetylase that has been linked to longevity and has been suggested to confer beneficial effects that counter aging‐associated deterioration. Muscle ...repair is dependent upon satellite cell function, which is reported to be reduced with aging; however, it is not known if this is linked to an aging‐suppression of SIRT1. This study tested the hypothesis that Sirtuin 1 (SIRT1) overexpression would increase the extent of muscle repair and muscle function in older mice.
Methods
We examined satellite cell dependent repair in tibialis anterior, gastrocnemius, and soleus muscles of 13 young wild‐type mice (20–30 weeks) and 49 older (80+ weeks) mice that were controls (n = 13), overexpressed SIRT1 in skeletal muscle (n = 14), and had a skeletal muscle SIRT1 knockout (n = 12) or a satellite cell SIRT1 knockout (n = 10). Acute muscle injury was induced by injection of cardiotoxin (CTX), and phosphate‐buffered saline was used as a vector control. Plantarflexor muscle force and fatigue were evaluated before or 21 days after CTX injection. Satellite cell proliferation and mitochondrial function were also evaluated in undamaged muscles.
Results
Maximal muscle force was significantly lower in control muscles of older satellite cell knockout SIRT1 mice compared to young adult wild‐type (YWT) mice (P < 0.001). Mean contraction force at 40 Hz stimulation was significantly greater after recovery from CTX injury in older mice that overexpressed muscle SIRT1 than age‐matched SIRT1 knockout mice (P < 0.05). SIRT1 muscle knockout models (P < 0.05) had greater levels of p53 (P < 0.05 MKO, P < 0.001 OE) in CTX‐damaged tissues as compared to YWT CTX mice. SIRT1 overexpression with co‐expression of p53 was associated with increased fatigue resistance and increased force potentiation during repeated contractions as compared to wild‐type or SIRT1 knockout models (P < 0.001). Muscle structure and mitochondrial function were not different between the groups, but proliferation of satellite cells was significantly greater in older mice with SIRT1 muscle knockout (P < 0.05), but not older SIRT1 satellite cell knockout models, in vitro, although this effect was attenuated in vivo after 21 days of recovery.
Conclusions
The data suggest skeletal muscle structure, function, and recovery after CTX‐induced injury are not significantly influenced by gain or loss of SIRT1 abundance alone in skeletal muscle; however, muscle function is impaired by ablation of SIRT1 in satellite cells. SIRT1 appears to interact with p53 to improve muscle fatigue resistance after repair from muscle injury.
Purpose We describe our experience with surgical management of bisphosphonate-related osteonecrosis of the jaws (BRONJ). Materials and Methods The data included 33 BRONJ cases treated surgically by a ...single surgeon at the Hospital of the University of Pennsylvania. Results Of the 30 debridement patients, 25 (including 1 sequestrectomy patient who required formal debridement) healed completely. Of the 30 patients who underwent surgical debridement, 18 healed following this initial treatment and remained healed. Of the 4 patients requiring sequestrectomy, 3 healed after the initial treatment. Thus, 28 of 33 patients healed completely with complete mucosal coverage and elimination of pain. Four patients developed occurrence of BRONJ at a separate site. All 4 patients were treated with our surgery protocol and remain healed. Thus, 32 of 37 BRONJ occurrences have healed with our surgical debridement protocol or sequestrectomy. The follow-up range was 1 to 40 months (average 10.7). Conclusions The results of our case series have shown that surgical debridement can be successful in treating BRONJ.
To compare remineralization of enamel subsurface lesions by fluoride dentifrices with added calcium in a double-blind, randomized, cross-over, in situ study.
Human enamel with subsurface lesions were ...prepared and inserted into intra-oral appliances worn by volunteers. A slurry (1 g toothpaste/4 ml H2O) was rinsed for 60 s, 4 times per day for 14 days. Seven toothpastes were tested: (i) 1450 ppm F (NaF), (ii) 5000 ppm F (NaF), (iii) 1450 ppm F (MFP) with calcium sodium phosphosilicate (CSP), (iv) 1450 ppm F (MFP) with CaCO3/Arg, (v) 1150 ppm F (SnF2) with amorphous calcium phosphate (ACP), (vi) 1100 ppm F (NaF) with casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) and (vii) 5000 ppm F (NaF) with functionalized tri-calcium phosphate (TCP). Total (acid soluble) and bioavailable (water soluble) calcium, inorganic phosphate and fluoride levels of the dentifrices were measured using ion chromatography (F/MFP) and spectrophotometry (Ca and inorganic phosphate). Enamel lesion mineral content was measured using transverse microradiography. Data were statistically analysed using a linear mixed model.
All calcium and fluoride containing toothpastes released > 90% of bioavailable fluoride and were superior to the respective fluoride alone toothpastes in remineralization of enamel subsurface lesions. The level of remineralization followed the order: CPP-ACP/1l00 ppm F > ACP/1150 ppm F = TCP/5000 ppm F > 5000 ppm F = CaCO3/Arg/1450 ppm F = CSP/1450 ppm F > 1450 ppm F. Bioavailable calcium levels significantly correlated with enhanced remineralization of enamel subsurface lesions.
Bioavailable calcium in fluoride dentifrices enhanced remineralization of enamel subsurface lesions.
The Arylhydrocarbon Receptor (AhR), a member of the Per-ARNT-SIM transcription factor family, has been as a potential new target to treat breast cancer sufferers. A series of 2-phenylacrylonitriles ...targeting AhR has been developed that have shown promising and selective activity against cancerous cell lines while sparing normal non-cancerous cells. A quantitative structure–activity relationship (QSAR) modeling approach was pursued in order to generate a predictive model for cytotoxicity to support ongoing synthetic activities and provide important structure-activity information for new structure design. Recent work conducted by us has identified a number of compounds that exhibited false positive cytotoxicity values in the standard MTT assay. This work describes a good quality model that not only predicts the activity of compounds in the MCF-7 breast cancer cell line, but was also able to identify structures that subsequently gave false positive values in the MTT assay by identifying compounds with aberrant biological behavior. This work not only allows the design of future breast cancer cytotoxic activity in vitro, but allows the avoidance of the synthesis of those compounds anticipated to result in anomalous cytotoxic behavior, greatly enhancing the design of such compounds.
Despite the importance of earthworms for soil formation, more is needed to know about how Pre-Columbian modifications to soils and the landscape. Gaining a deeper understanding is essential for ...comprehending the historical drivers of earthworm communities and the development of effective conservation strategies in the Amazon rainforest. Human disturbance can significantly impact earthworm diversity, especially in rainforest soils, and in the particular case of the Amazonian rainforest, both recent and ancient anthropic practices may be important. Amazonian Dark Earths (ADEs) are fertile soils found throughout the Amazon Basin, created by sedentary habits and intensification patterns of pre-Colombian societies primarily developed in the second part of the Holocene period. We have sampled earthworm communities in three Brazilian Amazonian (ADEs) and adjacent reference soils (REF) under old and young forests and monocultures.
To better assess taxonomic richness, we used morphology and the barcode region of the COI gene to identify juveniles and cocoons and delimit Molecular Operational Taxonomic Units (MOTUs). Here we suggest using Integrated Operational Taxonomical units (IOTUs) which combine both morphological and molecular data and provide a more comprehensive assessment of diversity, while MOTUs only rely on molecular data. A total of 970 individuals were collected, resulting in 51 taxonomic units (IOTUs, MOTUs, and morphospecies combined). From this total, 24 taxonomic units were unique to REF soils, 17 to ADEs, and ten were shared between both soils. The highest richness was found in old forest sites for ADEs (12 taxonomic units) and REFs (21 taxonomic units). The beta-diversity calculations reveal a high species turnover between ADEs and REF soils, providing evidence that ADEs and REFs possess distinct soil biota. Furthermore, results suggest that ADE sites, formed by Pre-Columbian human activities, conserve a high number of native species in the landscape and maintain a high abundance, despite their long-term nature.
Display omitted
•Amazonian Dark Earths show an exclusive pool of earthworm species.•Integrated Operational Taxonomic Units (IOTUs) robustly assess earthworm diversity.•IOTUs allow the use of data based on immature individuals and cocoons.•Current land use affects earthworm abundance and diversity.•The historical land use explains the species pool.
Ancient DNA provides a powerful means to investigate the timing, rate and extent of population declines caused by extrinsic factors, such as past climate change and human activities. One species ...probably affected by both these factors is the arctic fox, which had a large distribution during the last glaciation that subsequently contracted at the start of the Holocene. More recently, the arctic fox population in Scandinavia went through a demographic bottleneck owing to human persecution. To investigate the consequences of these processes, we generated mitogenome sequences from a temporal dataset comprising Pleistocene, historical and modern arctic fox samples. We found no evidence that Pleistocene populations in mid-latitude Europe or Russia contributed to the present-day gene pool of the Scandinavian population, suggesting that postglacial climate warming led to local population extinctions. Furthermore, during the twentieth-century bottleneck in Scandinavia, at least half of the mitogenome haplotypes were lost, consistent with a 20-fold reduction in female effective population size. In conclusion, these results suggest that the arctic fox in mainland Western Europe has lost genetic diversity as a result of both past climate change and human persecution. Consequently, it might be particularly vulnerable to the future challenges posed by climate change. This article is part of a discussion meeting issue 'The past is a foreign country: how much can the fossil record actually inform conservation?'
PDF
