Key mechanistic features of swelling and blistering of helium-ion-irradiated tungsten

Helium-ion-induced swelling and blistering of single-crystal tungsten is investigated using a Helium Ion Microscope for site-specific dose-controlled irradiation (at 25 keV) with analysis by Helium Ion Microscopy, Atomic Force Microscopy and Transmission Electron Microscopy (cross-sectioning by Focused Ion Beam milling). We show that the blister cavity forms at a depth close to the simulated helium peak and that nanobubbles coalesce to form nanocracks within the envelope of the ion stopping range, swelling the blister shell. These results provide the first direct experimental evidence for the interbubble fracture mechanism proposed in the framework of the gas pressure model for blister formation

Helicobacter pylori virulence factors in duodenal ulceration: A primary cause or a secondary infection causing chronicity

Reports from countries with a high prevalence of Helicobacter pylori. (H pylori) infection do not show a proportionately high prevalence of duodenal ulceration, suggesting the possibility that H pylori cannot be a primary cause of duodenal ulceration. It has been mooted that this discrepancy might be explained by variations in the prevalence of virulence factors in different populations. The aim of this paper is to determine whether the published literature gives support to this possibility. The relevant literature was reviewed and analyzed separately for countries with a high and low prevalence of H pylori infection and virulence factors. Although virulent strains of H pylori were significantly more often present in patients with duodenal ulcer than without the disease in countries with a low prevalence of H pylori infection in the population, there was no difference in the prevalence of virulence factors between duodenal ulcer, non - ulcer dyspepsia or normal subjects in many countries, where the prevalence of both H pylori infection and of virulence factors was high. In these countries, the presence of virulence factors was not predictive the clinical outcome. To explain the association between virulence factors and duodenal ulcer in countries where H pylori prevalence is low, only two papers were found that give little support to the usual model proposed, namely that organisms with the virulence factors are more likely than those without them to initiate a duodenal ulcer. We offer an alternative hypothesis that suggests virulence factors are more likely to interfere with the healing of a previously produced ulcer. The presence of virulence factors only correlates with the prevalence of duodenal ulcer in countries where the prevalence of H pylori is low. There is very little evidence that virulence factors initiate duodenal ulceration, but they may be related to failure of the ulcer to heal

Precise role of H pylori in duodenal ulceration

The facts that H pylori infection is commoner in duodenal ulcer (DU) patients than in the normal population, and that eradication results in most cases being cured, have led to the belief that it causes DU. However, early cases of DU are less likely than established ones to be infected. H pylori-negative cases are usually ascribed to specific associated factors such as non-steroidal anti-inflammatory drugs (NSAIDs), Crohn’s disease, and hypergastrinaemia, but even after excluding these, several H pylori-negative cases remain and are particularly common in areas of low prevalence of H pylori infection. Moreover, this incidence of H pylori negative DU is not associated with a fall in overall DU prevalence when compared with countries with a higher H pylori prevalence. In countries with a high H pylori prevalence there are regional differences in DU prevalence, but no evidence of an overall higher prevalence of DU than in countries with a low H pylori prevalence. There is no evidence that virulence factors are predictive of clinical outcome. After healing following eradication of H pylori infection DU can still recur. Medical or surgical measures to reduce acid output can lead to long-term healing despite persistence of H pylori infection. Up to half of cases of acute DU perforation are H pylori negative. These findings lead to the conclusion that H pylori infection does not itself cause DU, but leads to resistance to healing, i.e., chronicity. This conclusion is shown not to be incompatible with the universally high prevalence of DU compared with controls

Localised decline in colonies of the short-tailed shearwater: an explanation

Historical declines in local populations of the short-tailed shearwater Puffinus tenuirostris in the Furneaux Group are reviewed; particular attention is paid to information collected on Big Green Island, off Whitemark, Flinders Island. Disease, predators, and introduced stock are dismissed as causative agents in reported declines of colonies, as is changing vegetation. It is proposed that over-harvesting, initially of all stages and later of young, provides an explanation of such reductions, one which is demonstrated using a simple, deterministic model

Use of Force against Non-state Actors and the Circumstance Precluding Wrongfulness of Self-Defence

AbstractThe right of self-defence against non-state actors is increasingly invoked and accepted in the practice of states. However, the recognition of this right must overcome a fundamental obstacle: that of explaining why the rights of the host state, in particular its right of territorial sovereignty, is not infringed by the self-defensive force used within its territory. In practice, states invoking self-defence against non-state actors rely on the involvement of the host state with those actors to justify the use of force in that state's territory. It is not clear, from a legal standpoint, how to rationalize the fact of involvement as a form of legal justification. For some, involvement amounts to attribution. For others, involvement is a form of complicity. For others still, involvement may entail a breach of the host state's due diligence obligation to protect the rights of other states in its territory. All of these solutions are deficient in some way, and have failed to receive general endorsement. This article considers whether there may be a different, as yet neglected, solution: self-defence as a circumstance precluding wrongfulness. The article shows that this is not a perfect solution either, since positive law remains uncertain on this point. Nevertheless, it is a solution that may provide a better normative framework for the development of the law of self-defence against non-state actors.This is the author accepted manuscript. The final version is available from Cambridge University Press via https://doi.org/10.1017/S092215651600058

RESILIENSI PADA REMAJA DENGAN ORANGTUA YANG MENGALAMI KONFLIK ANTARA KELUARGA DAN PEKERJAAN

Kemampuan individu untuk bertahan bahkan menghasilkan suatu prestasi kehidupan dalam situasi yang penuh hambatan sering disebut dengan istilah resiliensi (resilience). Resiliensi yang juga dapat dimiliki oleh remaja merupakan kemampuan yang ada pada diri remaja untuk bangkit kembali dari pengalaman buruk, mengendalikan tekanan hidup sehari-hari, dan tetap produktif. Mesten dan Gewirtz (2006) menjelaskan bahwa resiliensi yang berasal dari bahasa latin resilire (untuk mundur atau meloncat kembali) adalah sebuah konsep umum terkait dengan adaptasi positif dalam konteks tantangan. Penelitian ini bertujuan untuk mengetahui tingkat konflik yang terjadi pada orangtua dan memahami resiliensi pada remaja dengan orangtua yang menglami konflik antara keluarga dan pekerjaan. Metode penggabungan antara kuantitatif dan kualitatif dipilih oleh peneliti untuk mencapai tujuan penelitian ini. Responden penelitian ini diambil dari populasi siswa Sekolah Menengah Al Firdaus, Surakarta. Penelitian ini menggunakan skala konflik kerja-keluarga yang dianalisis dengan total skor dan menggunakan kuesioner terbuka tentang resiliensi yang dianalisis dengan analisis kualitatif. Hasil menunjukkan bahwa 52 % orangtua dari populasi dalam penelitian ini memiliki konflik antara keluarga dan pekerjaan yang tergolong sedang, 29 % untuk kategori agak tinggi, 28 % agak rendah, dan 2 % tinggi. Remaja dalam kondisi konflik yang dialami orangtua terkait keluarga dan pekerjaan ternyata mampu memiliki sikap resilien meski mengalami pengalaman-pengalaman yang buruk. Sikap resilien tersebut mencakup dapat bangkit kembali ketika mendapat kegagalan dan mampu mengendalikan tekanan-tekanan hidup sehingga tetap produktif. Bangkit kembali ketika mendapat kegagalan diwujudkan dengan upaya positif yaitu memandang positif kegagalan, tetap berusaha, optimis, dan berdoa

Blaney-Morin-Nigeria (BMN) Evapotranspiration Model (A Technical Note)

Duru [1] presented a modified form of the Blaney-Morin potential evapotranspiration equation christened Blaney-Morin- Nigeria (BMN) Evapotranspiration (ET) model for use in Nigeria. In this work, Duru recognize the very wide variability of relative humidity in Nigeria and consequently the very important role this parameter is bound to play in the evapotranspiration process in this geographical region (Nigeria). Thus he (Duru) correctly surmised that any Et model that would reasonably estimate Potential evapotranspiration (PET) in Nigeria must involve humidity term as a crucial parameter

The role of libraries in curbing drug abuse among adolescent boys in Nigeria: A theoretical examination

This study examines the role of libraries in curbing drug abuse among adolescent boys in Nigeria. The study discovered that substance abuse is on the increase. It is one of the major social problems plaguing Nigerian society. Although different classes of people are getting involved in the despicable act of drug abuse, the trend is disturbingly high among  adolescent boys. The chronological age and other peculiarities associated with adolescence predispose this category of youths to experiment with  mood-altering substances as recourse to ease off the unavoidable stresses and strains of life. The findings dovetail with the basic assumptions of  Social Learning theory, which formed the theoretical framework to this  study. That is, adolescent boys are easily swayed by the destructive  influence of media advertisements, peer influence and pressure, and indeed, antisocial adults who they see as role models. The period of  adolescence is characterised by a high propensity to make amorous  advances towards the opposite sex which some boys believe that can be  achieved under the influence of psychoactive substances. The study  recommends that stakeholders on youth development and empowerment should organise regular intervention programmes with adolescents in their various schools and communities so as to sensitise them on the dangers of drug abuse, and how to stay away from illicit drug culture. Adolescents should be properly guided and encouraged to spend a great deal of their time in libraries studying to keep abreast of current trends in the vexed issue of substance abuse.Keywords: Adolescent Boys, Curbing, Drug Abuse, Libraries, Role, Theoretical Examinatio

Total Carotenoids, Tocopherols and Free fatty Acids Levels of Palm Oils Produced from small Scale Mills in Ovia - North East Local Government area of Edo State-Nigeria

This research was conducted to determine the total carotenoids, tocopherols and Free Fatty Acid(FFA) levels of oils produced from small scale mills and to evaluate their antioxidant effects. The study areas were located in Ovia-North East Local Government area of Edo State. The methods of harvesting, processing of the fruits and the storage of the oils were observed because of the positive effects the latter have on quality. Samples of palm oil were collected in duplicates with 100ml screw cap glass sample bottles from the storage drums of the ten (10) small scale mills.The total tocopherols and carotenoids of the oil samples were determined by the AOCS methods. The moisture content of the oils was determined with an electronic moisture analyser.The Free Fatty Acid was determined by the titrimetric method of sodium hydroxide. The results indicated that most of the oils were prone to oxidation and hydrolysis as their moisture (between 0.15 ± 0.01% and 0.53 ± 0.03%), tocopherols (between19.50 ± 0.10mg/100g and 51.0 ± 0.00mg/100g) and carotenoids (between 24.40 ± 0.10mg/100g and 65.0 ± 0.20mg/100g) values  suggest. Statistical analysis revealed that significant difference exists between the mean of each of the parameters of the oil sample analyzed. The FFA results indicated that the oils were oxidized which suggested that the the carotenoids and tocopherols did not play their expected roles because their antioxidant limit exceeded.Keywords: Carotenoids, Tocopherols, Moisture, Free FattyAcids, Small Scale Mills, Palm oi

An Observational Cohort Study on Delayed-Onset Infections after Mandibular Third-Molar Extractions.

OBJECTIVES: The purpose of the present study was to investigate the occurrence and clinical features of delayed-onset infections after mandibular third-molar extractions. METHOD AND MATERIALS: An observational cohort study was conducted on 179 patients undergoing mandibular third-molar extraction between January 2013 and December 2015, for a total of 217 extractions. Data were recorded at the time of extraction (T0), on suture removal seven days later (T1), and 30 days after the extraction, when patients were contacted and asked about their healing process (T2). The statistical analysis was performed with nonparametric tests. A p value lower than 0.05 was considered statistically significant. RESULTS: Eight delayed-onset infections were recorded, amounting to 3.7% of all extractions. The median time elapsing from the extraction to the delayed-onset infection was 35 days (IQR 28-40; min 24-max 49). Younger age and longer surgical procedures seemed to be more often associated with this complication. CONCLUSION: Delayed-onset infections after third-molar extractions are relatively rare postoperative complications characterized by a swelling, usually with a purulent discharge. Patients should be informed of this possibility, which might develop even several weeks after the extraction