Varieties and the terms of trade

This paper analyzes the dynamic adjustment of the terms of trade in an intertemporal, two country model with endogenous product variety. In the base model, all workers are identical. In an extended version, the development of new varieties requires skilled labor while manufacturing uses skilled and unskilled labor. In the model without skill, a population increase in one of the countries has no effect on its terms of trade, not even in the short run. In the model with skill, the terms of trade initially worsen, but eventually return to their original level. The terms of trade immediately and permanently worsen in response to a productivity increase in manufacturing. However, they gradually improve if the productivity in variety research rises. If productivity in both activities rises equiproportionally, the terms of trade respond in the same manner as after a population shock.

PENGARUH PERSEPSI WISATAWAN TERHADAP PERILAKU VANDALISME DI TAMAN WISATA ALAM SITU PATENGGANG KABUPATEN BANDUNG

Vandalisme merupakan tindakan yang dapat merusak lingkungan. Vandalisme dapat terjadi dimana saja, terlebih tempat wisata yang ramai dikunjungi oleh wisatawan. Taman Wisata Alam Situ Patenggang Kabupaten Bandung merupakan satu dari sekian banyak tempat wisata yang diminati di Jawa Barat, tepatnya di Kabupaten Bandung. Di lokasi tersebut ditemukan banyak sekali coretan tangan-tangan jahil, serakan sampah, atau bahkan sisa bekas pembakaran sampah dan daun kering. Dilatarbelakangi hal tersebut, maka perlu diadakan penelitian mengenai persepsi wisatawan terhadap lingkungan, agar diketahui bagaimana cara wisatawan memandang lingkungan. Upaya tersebut dilakukan agar mampu membuat kebijakan atau strategi agar dapat meminimalisir aksi vandalisme oleh wisatawan di Taman Wisata Alam Situ Patenggang. Dalam penelitian ini menggunaka metode deskriptif, dengan pendekatan kuantitatif. Dengan menyelidiki kondisi dan keadaan faktual yang terjadi di Taman Wisata Alam Situ Patenggang lalu kemudian memaparkan hasil temuan dalam bentuk laporan penelitian. Usia, latar belakang pendidikan ternyata memberi pandangan yang berbeda mengenai lingkungan. Dengan melakukan penelitian ini, didapat bagaimana persepsi wisatawan sebenarnya dan bagaimana pengaruhnya terhadap perilaku vandalisme yang dilakukan di Taman Wisata Alam Situ Patenggang Kabupaten Bandung. Dengan hasil sebesar 37,8% perilaku vandalisme dipengaruhi oleh persepsi wisatawan terhadap lingkungan. ---------- Vandalism is an act that can damage the environment. Vandalism can occur anywhere, especially tourist spot visited by tourists. Natural Park of Situ Patenggang Bandung District, is one of the many sights of interest in West Java, precisely in Bandung District. At that location found a lot of graffiti hands of ignorant, jumble trash, or even the rest of the former incinerators and dry leaves. Against the backdrop of this, it is necessary to research on the perception of tourists about the environment, in order to know how they look at the environmental rating. Efforts are made to be able to make policy or strategy in order to minimize vandalism by tourists in Natural Park of Situ Patenggang. In this study make use descriptive method, with a quantitative approach. By investigating the conditions and factual circumstances that occurred in the Natural Park of Situ Patenggang and then describes the findings in the form of research reports. Ages, educational background turns giving different views on the environment. By doing this research, how the perception of tourists will come true and how it affects the behavior of vandalism committed in the Natural Park of Situ Patenggang Bandung District. With a yield of 37.8 % vandalism behavior is influenced by the perception of tourists on the environment

Lagrange Anchor and Characteristic Symmetries of Free Massless Fields

A Poincar\'e covariant Lagrange anchor is found for the non-Lagrangian relativistic wave equations of Bargmann and Wigner describing free massless fields of spin $s>1/2$ in four-dimensional Minkowski space. By making use of this Lagrange anchor, we assign a symmetry to each conservation law and perform the path-integral quantization of the theory

Simple steps to develop trial follow-up procedures.

BACKGROUND: Loss to follow-up in randomised controlled trials reduces statistical power and increases the potential for bias. Almost half of all trials fail to achieve their follow-up target. Statistical methods have been described for handling losses to follow-up and systematic reviews have identified interventions that increase follow-up. However, there is little guidance on how to develop practical follow-up procedures. This paper describes the development of follow-up procedures in a pilot randomised controlled trial of a sexual health intervention that required participants to provide and return questionnaires and chlamydia test samples in the post. We identified effective methods to increase follow-up from systematic reviews. We developed and tested prototype procedures to identify barriers to follow-up completion. We asked trial participants about their views on our follow-up procedures and revised the methods accordingly. RESULTS: We identified 17 strategies to increase follow-up and employed all but five. We found that some postal test kits do not fit through letterboxes and that that the test instructions were complicated. After identifying the appropriate sized test kit and simplifying the instructions, we obtained user opinions. Users wanted kits to be sent in coloured envelopes (so that they could identify them easily), with simple instructions and questionnaires and wanted to be notified before we sent the kits. We achieved 92 % (183/200) overall follow-up for the postal questionnaire at 1 month and 82 % (163/200) at 12 months. We achieved 86 % (171/200) overall follow-up for the postal chlamydia test at 3 months and 80 % (160/200) at 12 months. CONCLUSIONS: By using established methods to increase follow-up, testing prototype procedures and seeking user opinions, we achieved higher follow-up than previous sexual health trials. However, it is not possible to determine if the increase in response was due to our follow-up procedures. TRIAL REGISTRATION: Current Controlled Trials ISRCTN02304709 Date of registration: 27 March 2013

Erratum to: Simple steps to develop trial follow-up procedures.

Unfortunately, the original version of this article [1] contained an error. There were errors in the reference numbers in Additional file 1. This has now been corrected and Additional file 1 is included here with the correct reference numbers

Human immunodeficiency virus rebound after suppression to < 400 copies/mL during initial highly active antiretroviral therapy regimens, according to prior nucleoside experience and duration of suppression

This study evaluated 1433 human immunodeficiency virus (HIV)-infected patients starting highly active antiretroviral therapy (HAART), 409 (28%) of whom had prior nucleoside experience and achieved an HIV load of <400 copies/mL by 24 weeks of therapy. Three hundred seven patients experienced virus rebound during a total of 2773.3 person-years of follow-up. There was a higher rate of virus rebound among the patients with pre-HAART nucleoside experience (relative hazard [RH], 2.86; 95% confidence interval, 2.22-3.84; P < .0001) and a decreasing rate of virus rebound with increasing duration of virus suppression (i.e., time since achieving a virus load of <400 HIV RNA copies/mL) among both the nucleoside-experienced and naive patients (P < .0001), but the difference between the groups persisted into the third year of follow-up (P = .0007). Even patients who had experienced <2 months of nucleoside therapy before beginning HAART had an increased risk of virus rebound (RH, 1.95; P = .009). It appears that only a small period of pre-HAART nucleoside therapy is sufficient to confer a disadvantage, in terms of risk of virus rebound, that persists for several years

Specific Internalisation of Gold Nanoparticles into Engineered Porous Protein Cages via Affinity Binding

Porous protein cages are supramolecular protein self-assemblies presenting pores that allow the access of surrounding molecules and ions into their core in order to store and transport them in biological environments. Protein cages’ pores are attractive channels for the internalisation of inorganic nanoparticles and an alternative for the preparation of hybrid bioinspired nanoparticles. However, strategies based on nanoparticle transport through the pores are largely unexplored, due to the difficulty of tailoring nanoparticles that have diameters commensurate with the pores size and simultaneously displaying specific affinity to the cages’ core and low non-specific binding to the cages’ outer surface. We evaluated the specific internalisation of single small gold nanoparticles, 3.9 nm in diameter, into porous protein cages via affinity binding. The E2 protein cage derived from the Geobacillus stearothermophilus presents 12 pores, 6 nm in diameter, and an empty core of 13 nm in diameter. We engineered the E2 protein by site-directed mutagenesis with oligohistidine sequences exposing them into the cage’s core. Dynamic light scattering and electron microscopy analysis show that the structures of E2 protein cages mutated with bis- or penta-histidine sequences are well conserved. The surface of the gold nanoparticles was passivated with a self-assembled monolayer made of a mixture of short peptidols and thiolated alkane ethylene glycol ligands. Such monolayers are found to provide thin coatings preventing non-specific binding to proteins. Further functionalisation of the peptide coated gold nanoparticles with Ni2+ nitrilotriacetic moieties enabled the specific binding to oligohistidine tagged cages. The internalisation via affinity binding was evaluated by electron microscopy analysis. From the various mutations tested, only the penta-histidine mutated E2 protein cage showed repeatable and stable internalisation. The present work overcomes the limitations of currently available approaches and provides a new route to design tailored and well-controlled hybrid nanoparticles

Dynamic modelling and response characteristics of a magnetic bearing rotor system including auxiliary bearings

Auxiliary bearings are a critical feature of any magnetic bearing system. They protect the soft iron core of the magnetic bearing during an overload or failure. An auxiliary bearing typically consists of a rolling element bearing or bushing with a clearance gap between the rotor and the inner race of the support. The dynamics of such systems can be quite complex. It is desired to develop a rotor-dynamic model and assess the dynamic behavior of a magnetic bearing rotor system which includes the effects of auxiliary bearings. Of particular interest is the effects of introducing sideloading into such a system during failure of the magnetic bearing. A model is developed from an experimental test facility and a number of simulation studies are performed. These results are presented and discussed

Sexual health interventions delivered to participants by mobile technology: a systematic review and meta-analysis of randomised controlled trials

Background: The use of mobile technologies to prevent STIs is recognised as a promising approach worldwide; however, evidence has been inconclusive, and the field has developed rapidly. With about 1 million new STIs a day globally, up-to-date evidence is urgently needed. // Objective: To assess the effectiveness of mobile health interventions delivered to participants for preventing STIs and promoting preventive behaviour. // Methods: We searched seven databases and reference lists of 49 related reviews (January 1990–February 2020) and contacted experts in the field. We included randomised controlled trials of mobile interventions delivered to adolescents and adults to prevent sexual transmission of STIs. We conducted meta-analyses and assessed risk of bias and certainty of evidence following Cochrane guidance. // Results: After double screening 6683 records, we included 22 trials into the systematic review and 20 into meta-analyses; 18 trials used text messages, 3 used smartphone applications and 1 used Facebook messages as delivery modes. The certainty of evidence regarding intervention effects on STI/HIV occurrence and adverse events was low or very low. There was moderate certainty of evidence that in the short/medium-term text messaging interventions had little or no effect on condom use (standardised mean differences (SMD) 0.02, 95% CI −0.09 to 0.14, nine trials), but increased STI/HIV testing (OR 1.83, 95% CI 1.41 to 2.36, seven trials), although not if the standard-of-care control already contained an active text messaging component (OR 1.00, 95% CI 0.68 to 1.47, two trials). Smartphone application messages also increased STI/HIV testing (risk ratio 1.40, 95% CI 1.22 to 1.60, subgroup analysis, two trials). The effects on other outcomes or of social media or blended interventions is uncertain due to low or very low certainty evidence

Access to interpreting services in England: secondary analysis of national data

Background: Overcoming language barriers to health care is a global challenge. There is great linguistic diversity in the major cities in the UK with more than 300 languages, excluding dialects, spoken by children in London alone. However, there is dearth of data on the number of non-English speakers for planning effective interpreting services. The aim was to estimate the number of people requiring language support amongst the minority ethnic communities in England. Methods: Secondary analysis of national representative sample of subjects recruited to the Health Surveys for England 1999 and 2004. Results: 298,432 individuals from the four main minority ethnic communities (Indian, Pakistani, Bangladeshi and Chinese) who may be unable to communicate effectively with a health professional. This represents 2,520,885 general practice consultations per year where interpreting services might be required. Conclusion: Effective interpreting services are required to improve access and health outcomes of non-English speakers and thereby facilitate a reduction in health inequalities