The Peculiar Velocity Function of Galaxy Clusters

The peculiar velocity function of clusters of galaxies is determined using an accurate sample of cluster velocities based on Tully-Fisher distances of Sc galaxies (Giovanelli et al 1995b). In contrast with previous results based on samples with considerably larger velocity uncertainties, the observed velocity function does not exhibit a tail of high velocity clusters. The results indicate a low probability of $\lesssim$\,5\% of finding clusters with one-dimensional velocities greater than $\sim$ 600 {\kms}. The root-mean-square one-dimensional cluster velocity is 293$\pm$28 {\kms}. The observed cluster velocity function is compared with expectations from different cosmological models. The absence of a high velocity tail in the observed function is most consistent with a low mass-density ($\Omega \sim$0.3) CDM model, and is inconsistent at $\gtrsim 3 \sigma$ level with $\Omega$= 1.0 CDM and HDM models. The root-mean-square one-dimensional cluster velocities in these models correspond, respectively, to 314, 516, and 632 {\kms} (when convolved with the observational uncertainties). Comparison with the observed RMS cluster velocity of 293$\pm$28 {\kms} further supports the low-density CDM model.Comment: revised version accepted for publication in ApJ Letters, 18 pages, uuencoded PostScript with 3 figures included; complete paper available through WWW at http://www.astro.princeton.edu/~library/prep.htm

Guidelines for Negotiating Scientific Collaboration

Whether it's sharing reagents with a laboratory on the other side of the world or working with the postdoc at the neighboring bench, some simple rules of collaboration might help

Primary cultures of chick osteocytes retain functional gap junctions between osteocytes and between osteocytes and osteoblasts

The inaccessibility of osteocytes due to their embedment in the calcified bone matrix in vivo has precluded direct demonstration that osteocytes use gap junctions as a means of intercellular communication. In this article, we report successfully isolating primary cultures of osteocytes from chick calvaria, and, using anti-connexin 43 immunocytochemistry, demonstrate gap junction distribution to be comparable to that found in vivo. Next, we demonstrate the functionality of the gap junctions by (1) dye coupling studies that showed the spread of microinjected Lucifer Yellow from osteoblast to osteocyte and between adjacent osteocytes and (2) analysis of fluorescence replacement after photobleaching (FRAP), in which photobleaching of cells loaded with a membrane-permeable dye resulted in rapid recovery of fluorescence into the photobleached osteocyte, within 5 min postbleaching. This FRAP effect did not occur when cells were treated with a gap junction blocker (18 alpha-glycyrrhetinic acid), but replacement of fluorescence into the photobleached cell resumed when it was removed. These studies demonstrate that gap junctions are responsible for intercellular communication between adjacent osteocytes and between osteoblasts and osteocytes. This role is consistent with the ability of osteocytes to respond to and transmit signals over long distances while embedded in a calcified matrix. </p

Developmental research of sustainable technologies to minimise problematic road embankment settlements

Challenging, problematic and non-uniform ground conditions are a night mare to geotechnical engineers tasked with the design and construction of buildings and transport infrastructure. These often suffer undesirable structural settlements. Designing within the current understanding of geotechnics; settlement in peat and organic soils need to be recognised to include the known “primary and secondary consolidation characteristics” and the lesser known “tertiary consolidation phase”. These eventually contribute cumulatively to the consequential uneven and hazardous “bumpy road” surfaces. Undulating flexible road pavements result primarily from the transference of the heavy self-weight of the embankment fill to yielding and non-uniform subgrade. The adoption of conventional design/repair methods such as pile, vertical drain, soil replacement and soil stabilisation are expensive and inappropriate in very soft ground conditions. These then lead to unjustifiably high and repetitive maintenance costs. There being no one quick fix solution for all; pragmatic research must necessarily identify the best/progressively improved practical and sustainable solution. A viable solution is to develop criteria and explore the concept of a “masonry arch bridge structure/lintel-column structure” and adopting sustainable materials through pragmatic searching for appropriate recyclable waste materials. This will lead to the basis for a sustainable, innovative, strong, stiff, permeable composite mat structure that can be used on soft and/or yielding ground conditions. Conceptual lightweight fill technology including the popularly used expanded polystyrene (EPS) and the innovative composite mats recently being developed by the research team are outlined

COVID-19 first anniversary review of cases, hospitalization, and mortality in the UK

Introduction: The first confirmed COVID-19 case in UK dates to 11 January 2020, exhibiting its first peak during April 2020. The country has since been hit by another wave in the winter 2020, almost at the first anniversary of the pandemic.Areas covered: An in-depth analysis of the COVID-19 positive cases in the UK throughout the year, hospitalizations, patients in critical care, and COVID-19 associated deaths.Expert opinion: The COVID-19 associated hospital admission accounts to 15% of total COVID-19 positive cases in November 2020. The percentage of total COVID-19 positive patients in the country died from the disease was under 4% in November 2020. Total deaths in England (all-cause) from June to October 2020 were similar to the historic averages. Age was the single most determinator of COVID-19 associated mortality, 50 years or older accounted for 98% of total COVID deaths. Age distribution of COVID-19 associated deaths in 2020 was similar to all-cause mortality age distribution in 2019. There was no significant improvement in the survival rate of COVID-19 patients receiving critical care. This prompts an urgent need to invest in novel antiviral therapeutics to save the most vulnerable in the society

Perbedaan Hasil Belajar Siswa SMA Negeri 5 Palu melalui Penerapan Model Pembelajaran Kooperatif Tipe Course Review Horay dan Konvensional pada Materi Larutan Elektrolit dan Nonelektrolit

One of indicator that quality of education said to be good is when students able to apply what they have learned at school to deal with problems in their daily life. Learning in the classroom should not only focus on mastery of the materials but also how to create the atmosphereT in the classroom to be fun and interesting so that students are not bored and learning outcomes can be improved. Course Review Horay (CRH) is one of a model that can be applied. This research aims to find out the difference of learning outcome of SMA Negeri 5 Palu through cooperative learning model application of CRH on electrolyte and non electrolyte solutions material. Populations of this research are all students of grade X of SMA Negeri 5 Palu for Academic Year of 2012/2013 which are consists of seven classes. Sample of this research consist of two classes which are class XA with 28 students as experiment class and class XG with 27 students as control class which determined by purposive sampling. Data collection is conducted using test instrument such as chemistry learning achievement of Electrolyte and non electrolyte solutions material. Data from research result is tested using two parties t-test with prerequisite test which are; normality test and homogeneity test. Average score of students learning outcome using cooperative learning model CRH is 23.21 while the average score of students learning outcome who join the conventional teaching is 19.93. Based on the statistic analysis with statistic t-test is achieved thitung = 4.81 and this is in the rejection area of H0 which is -2.00 and 2.00. Therfore, it can be concluded that there is a difference of students learning outcome through Cooperative learning model application of CRH type and conventional to the students grade X of SMA Negeri 5 Palu

SV-wave with external force in saturated medium

There are past researches done for SV-wave with the absence of external force. This work aims to investigate the influence of external force in the propagation of SV-wave in the soluble and insoluble mediums. Isotropic wave model is derived for SV-wave with various forces in accordance to Duhamel Principle and their analytical solutions are used to compare with each other’s’ amplitudes. With the existence of high density fluid, diffusive waves with larger external force will induce higher amplitude. However, SV-waves are non-diffusive in low density medium and hence, this work concludes that wave diffusion by external force is subjected to the properties of the targeted medium

Meningkatkan Pemahaman Konsep Bagian-Bagian Tumbuhan Melalui Pembelajaran Kooperatif Tipe Student Teams Achievemen Division (STAD) Di Kelas IV SDN No.1 Inti Lero Tatari

Penelitian ini adalah Meningkatkan pemahaman konsep bagian-bagian tumbuhan melalui pembelajaran kooperatif tipe Student Teams Achievemen Division (STAD) di kelas IV SDN No.1 Inti Lero Tatari. Adapun tujuan penelitian ini adalah untuk mengetahui pemahaman siswa dalam pembelajaran konsep bagian – bagian tumbuhan melalui pembelajaran kooperatif tipe STAD, yang melibatkan 21 orang siswa yang terdiri dari 13 orang siswa laki – laki dan 8 orang siswa perempuan yang terdaftar pada tahun pelajaran 2013 – 2014. Penelitian ini menggunakan desain penelitian model Kemmis dan Mc Tanggart yang terdiri atas dua siklus. Di mana pada setiap siklus dilaksanakan dua kali pertemuan dikelas dan setiap siklus terdiri empat tahap yaitu perencanaan, pelaksanaan, observasi, dan refleksi. Dari hasil penelitian menunjukkan bahwa pada tindakan siklus I diperoleh ketuntasan klasikal 61,90% dan daya serap klasikal 73,33%. pada tindakan siklus II diperoleh ketuntasan klasikal 100% dan daya serap klasikal 86,66%. hal ini berarti pembelajaran pada siklus II telah memenuhi indikator keberhasilan. pada kegiatan pembelajaran dengan menerapkan model pembelajaran kooperatif tipe STAD dapat meningkatkan hasil belajar siswa kelas IV pada SDN No.1 Inti Lero Tatari

Mean reversion and convergence of ecological footprint in the MENA region: evidence from a fractional integration procedure.

This paper deals with the analysis of mean reversion and convergence of the ecological footprint (EF) in the MENA region. Using a long memory model based on fractional integration, we find that the results are very heterogeneous across countries depending on the assumptions made on the error term and the use of original versus logged data. Nevertheless, some conclusions can be obtained. Thus, mean reversion is decisively found in the case of Tunisia, and other countries showing some degree of reversion to the mean include Israel, Syria, Yemen, and Iran. Dealing with the issue of convergence within the MENA countries, similar conclusions hold and only Tunisia reports statistical evidence of convergence for the two types of errors. Additional evidence is found in the case of Syria, Yemen, and Jordania with uncorrelated errors and for Iran with autocorrelation. It is recommended that environmental policies targeted at stabilizing the trends in EF in the MENA region should not be indiscriminately applied in consideration of the heterogeneous nature of the series in the regionpost-print728 K