Directed Search on the Job, Heterogeneity, and Aggregate Fluctuations

We study a labor market where workers search for jobs both on the job and off the job. In the model, there are aggregate productivity shocks and match-specific shocks. We outline the proof of existence of an equilibrium which we call a block recursive equilibrium (BRE), in which individuals' decisions and market tightness are independent of the distribution of workers over wages or contracts. A critical assumption that is responsible for a BRE to exist is that search is directed by firms' posting of contracts. We explain why a BRE does exist under the assumption of directed search and why it does not under the assumption of random search. Finally, we generalize the proof of existence of a BRE to allow workers to be ex-ante heterogeneous with respect to some observable characteristics such as education and skill.Directed Search; On the Job Search; Heterogeneity; Aggregate Fluctuations

A Critical Analysis of the Effects of Colello v. SEC on International Securities Law Enforcement Agreements

The load carrying capacity of interbre joints are one of the key entities for build-up of strength inpaper materials. In order to gain insight in how to tailor the macroscopic properties of such materialsby chemical and/or mechanical treatments at a microscopic level, direct measurement of individualbre{bre crosses are typically performed. However, the state of loading in the interbre joint, intesting of individual bre{bre crosses, is in general very complex and an increased understandingfor how to evaluate the mechanical properties of interbre joints is desirable. In Paper A, amethod for manufacturing and measuring the strength of isolated interbre joints is presented. Themethod is applied to investigate the strength of bre{bre crosses at two dierent modes of loading.Also, an investigation on the manufacturing conditions is presented. The strength distribution ofindividually prepared bre{bre crosses is characterized and it was found that the median strengthin a peeling type of loading was about 20% compared to samples tested in the conventional shearingtype of loading. In Paper B, a procedure for evaluating interbre joint strength measurementsin terms of resultant forces and moments in the interbre joint region is presented. The methodis applied to investigate the state of loading in bre{bre crosses tested in peeling and shearing,respectively. It is shown that for a typical interbre joint strength test, the load components otherthan shear, cannot in general be neglected and is strongly dependent on the structural geometry ofthe bre{bre crosses. In Paper C, four distinctly dierent load cases; peeling, shearing, tearingand a biaxial type of loading was tested mechanically and evaluated numerically in order to gainmore information on how interbre joints behave in dierent modes of loading. In Paper D, thein uence of a chemical additive on the interbre joint strength is investigated on the microscopic(joint) scale and correlated to the eect previously observed on the macroscopic (sheet) scale. Xraymicrotomography and image analysis was used to understand structural changes in the brousnetwork in terms of the number of interbre joints as well as the average interbre joint contact area.The results showed that the median interbre joint strength increased by 18% upon adsorption, andthat the polyelectrolyte increased the number of contacts between the bres as well as an increasedarea of contact. In Paper E, the damage behaviour of individual interbre joints is analyzed. Froman extensive number of mechanical tests, the typical damage behaviour is identied and a failurecriterion is used to study the in uence of failure properties to give indications on how to tailor thematerial to optimize the joint strength.En av de viktigaste mekanismerna for den lastbarande formagan hos pappersmaterial ar brottegenskapernahos berfogarna. For att eektivt skraddarsy sadana materials egenskaper genom kemiskoch/eller mekanisk behandling samt for att forsta hur sadana modieringar paverkar egenskapernapa en mikroskopisk niva ar provning av individuella ber-ber-kors en allmant anvand metod. Belastningeni en berfog vid sadan provning ar dock generellt komplicerad och ytterligare kunskapom hur berfogars mekaniska egenskaper skall utvarderas ar onskvard. I Artikel A, presenterasen metod for tillverkning samt mekanisk provning av isolerade ber-kors vid tva olika typer avbelastning. Vidare undersoks hur torktrycket, torkmetoden samt graden av malning inverkar pafogstyrkan. Resultaten visar att brottlasten for en globalt akande belastning var omkring 20 % avbrottlasten for prov utforda med den konventionella skjuvande belastningen samt att styrkan hosindividuellt tillverkade berkors ar fordelade enligt en Weibull fordelning. I Artikel B, presenterasen numerisk metod for utvardering av fogstyrke-matningar med avseende pa kraft- och momentresultanternai gransytan mellan brerna. Metoden anvands for att studera belastningsmoden hosber-kors i tva principiellt olika lastfall. Resultaten visar att for ett typiskt berfogsprov, kan intelastkomponenterna, vid sidan av skjuvning, generellt forsummas da de ar starkt beroende avber-korsets geometri. I Artikel C, jamfors fogstyrkematningar under fyra principiellt olika lastfall; akande, skjuvande, rivande samt biaxiellt. De experimentella last-forskjutningskurvorna, samtde beraknade lastmoderna anvands for att undersoka vilket tillskott pa information de foreslagnalastfallen kan ge i hansyn till fogstyrkan hos massabrer. I Artikel D, undersoks en polymers (somabsorberats pa berytorna) inverkan pa saval berniva som pa natverksniva. Fiberfogstyrkan matsexperimentellt och eekten av den kemiska tillsatsen jamfors pa mikroskopisk niva (ber-kors) medtidigare uppmatt eekt pa makroskopisk niva (ark). Rontgentomogra och bildanalys anvands foratt undersoka de strukturella skillnaderna som uppstar i de brosa natverken vid absorption av enpolyamin och resultaten visar att antalet berfogar per berlangdenhet samt att medelkontaktareanokade. Resultaten visar ocksa att medianen av berfogsstyrkan okade med 18 %. Dessa eekter sammantagetar anledningen till varfor polyaminer, sasom PAH, ar sa eektiva for att oka torrstyrkanhos pappersmaterial. I Artikel E, karakteriseras skadebeteendet hos individuella berfogar franett omfattande antal matningar. Ett brottkriterium infors i den numeriska utvarderingsmetoden foratt studera skadebeteendet. Kanslighetsanalys och inverkan av brottparametrarna studeras ocksafor att ge indikationer pa hur egenskaperna kan skraddarsys for att optimera berfogstyrkan.QC 20140527BiMaC Innovatio

Transfer, similarity or lack of awareness? inconsistencies of German learners in the pronunciation of lot, thought, strut, palm and bath

The current study presents acoustic analyses of non-high back vowels and low central vowels in the lexical sets LOT, THOUGHT, STRUT, PALM and BATH as pronounced by German learners of English. The main objective is to show that learners of English at university level are highly inconsistent in approximating the vowels of their self-chosen target accents British English (BrE) and American English (AmE). To that end, the acoustic qualities of the English vowels of learners are compared to their native German vowels and to the vowels of native speakers of BrE and AmE. In order to facilitate statements about the effect of increased experience, the study differentiates between students in their first year at university and in their third year or later. The results obtained are highly variable: In some cases the learners transfer their L1 vowels to English, other cases show clear approximations to the target vowels, while other cases again document the production of new vowels neither found in German nor in English. However, close approximation to the target vowels only sometimes correlates with higher proficiency. This might be an indicator of a low level of awareness of systematic differences between the BrE and AmE vowel systems. But the data also indicate that the more advanced learners produce more distinct AmE BATH vowels and BrE THOUGHT vowels than the less advanced learners, which points to a partial increase of awareness resulting from increased experience. All in all it seems that raising the awareness of differences between target accents in L2 instruction is necessary if the envisage goal is for learners to reach near-native pronunciation

BRE modulates granulosa cell death to affect ovarian follicle development and atresia in the mouse

The BRE (brain and reproductive expression) gene, highly expressed in nervous and reproductive system organs, plays an important role in modulating DNA damage repair under stress response and pathological conditions. Folliculogenesis, a process that ovarian follicle develops into maturation, is closely associated with the interaction between somatic granulosa cell and oocyte. However, the regulatory role of BRE in follicular development remains undetermined. In this context, we found that BRE is normally expressed in the oocytes and granulosa cells from the primordial follicle stage. There was a reduction in follicles number of BRE mutant (BRE(−/−)) mice. It was attributed to increase the follicular atresia in ovaries, as a result of retarded follicular development. We established that cell proliferation was inhibited, while apoptosis was markedly increased in the granulosa cells in the absence of BRE. In addition, expressions of γ-H2AX (marker for showing DNA double-strand breaks) and DNA damage-relevant genes are both upregulated in BRE(−/−) mice. In sum, these results suggest that the absence of BRE, deficiency in DNA damage repair, causes increased apoptosis in granulosa cells, which in turn induces follicular atresia in BRE(−/−) mice

Exploring the role of materials in policy change: innovation in low energy housing in the UK

There remains uncertainty in models of the policy process about how and when radical change takes place. Most policy authors focus on explaining incremental change, and yet in practice a pattern of change described as punctuated equilibrium has been observed, with periods of stability interspersed with periods of rapid, abrupt change. It is argued here that the influence of materials and technologies—the substance of policy—must be incorporated into models of the policy process in order to help further our understanding of radical change. Concepts from science and technology studies concerning the inseparability of social and technical spheres are used to explore how people and materials interact to create opportunities for radical change. These ideas are particularly relevant to policy sectors comprising durable, capital-intensive infrastructure, such as housing. Drawing on examples from the UK housing sector, ideas about policy networks and large technical systems are synthesised to develop a more holistic, interdisciplinary account of policy change

Renewable energy in remote communities

This article is the result of a competitively tendered University-funded project, this brings together two major Government Policy areas: sustainable communities and use of carbon fuels, and is aimed at influencing the policy debate on the difficulties of linking remote communities to renewable energy production because of poor distribution networks. Linkage with the Sustainable Communities agenda is an essential ingredient, as the proposal is that the renewable energy technologies will be installed and maintained by the communities themselves

Ethanol Production from Non Food Tubers of Iles-iles (Amorphophallus campanulatus) using Hydrolyzes by Commercial Enzymes (α and β amylase) and Fermentation by Saccharomices cereviseae

The decrease of oil production caused the increase on the price of fossil fuels. This paper was investigated the possibility of Amorphophallus campanulatus or known as âiles-ilesâ by Javanese people, which is known have a high carbohydrate content, as a raw material to produce bioethanol. The first stage of the process was hydrolyzes the starch, combined by liquefaction and saccharification of the starch from âiles-ilesâ using α and β amylase. The process was followed by fermentation of glucose with the help of S. cerevisiae. To obtain the maximum ethanol content, several parameter had been studied, such as the type S. cerevisiae (pure, dry, wet and instant), the dosage of α-amylase, β-amylase and also DAP dosage as a nutrient support for S. cerevisiae. The result shows that the highest ethanol concentration obtained in fermentation using dry S. cereviseae for 72 h with 10.2% (v/v) of ethanol. The highest total sugar content by hydrolysis was achieved by 0.0032 mL α-amylase/g, while β-amylase was 0.0064 mL β-amylase/g (12.5% of glucose). This is show that with increasing of α and β amylase dosages, the total sugar formed was increased. The DAP (Diammonium phosphate) was used as a Nitrogen supply which is needed by S. cerevisiae to growth and as a results can increase the level of ethanol produced. The additional of DAP in the fermentation prove that it can enhance 8.45% (v/v) of ethanol. Therefore, it can be concluded that the highest levels of ethanol with conventional methods of âiles-ilesâ was obtained at 72 h using the dry S. cerevisiae, with 0.0032 and 0.0064 mL enzyme/g of α and β amylase, respectively. This result shows that the plant seems to be a potential raw material for bioethanol

‘O sibling, where art thou?’ – a review of avian sibling recognition with respect to the mammalian literature

Avian literature on sibling recognition is rare compared to that developed by mammalian researchers. We compare avian and mammalian research on sibling recognition to identify why avian work is rare, how approaches differ and what avian and mammalian researchers can learn from each other. Three factors: (1) biological differences between birds and mammals, (2) conceptual biases and (3) practical constraints, appear to influence our current understanding. Avian research focuses on colonial species because sibling recognition is considered adaptive where ‘mixing potential’ of dependent young is high; research on a wider range of species, breeding systems and ecological conditions is now needed. Studies of acoustic recognition cues dominate avian literature; other types of cues (e.g. visual, olfactory) deserve further attention. The effect of gender on avian sibling recognition has yet to be investigated; mammalian work shows that gender can have important influences. Most importantly, many researchers assume that birds recognise siblings through ‘direct familiarisation’ (commonly known as associative learning or familiarity); future experiments should also incorporate tests for ‘indirect familiarisation’ (commonly known as phenotype matching). If direct familiarisation proves crucial, avian research should investigate how periods of separation influence sibling discrimination. Mammalian researchers typically interpret sibling recognition in broad functional terms (nepotism, optimal outbreeding); some avian researchers more successfully identify specific and testable adaptive explanations, with greater relevance to natural contexts. We end by reporting exciting discoveries from recent studies of avian sibling recognition that inspire further interest in this topic