Extreme southern locations for moss sporophytes in Antarctica

Abundant immature sporophytes of the moss Pottia heimii are reported from the Lower Taylor Valley, McMurdo Dry Valleys and from Cape Chocolate, Victoria Land. These finds extend the reported southern limit for the occurrence of abundant moss sporophytes to 77° 55′S

Solid angle subtended by a cylindrical detector at a point source in terms of elliptic integrals

The solid angle subtended by a right circular cylinder at a point source located at an arbitrary position generally consists of a sum of two terms: that defined by the cylindrical surface ($\Omega_{cyl}$) and the other by either of the end circles ($\Omega_{circ}$). We derive an expression for $\Omega_{cyl}$ in terms of elliptic integrals of the first and third kinds and give similar expressions for $\Omega_{circ}$ using integrals of the first and second kinds. These latter can be used alternatively to an expression also in terms of elliptic integrals, due to Philip A. Macklin and included as a footnote in Masket (Rev. Sci. Instr., 28 (3), 191-197, 1957). The solid angle subtended by the whole cylinder when the source is located at an arbitrary location can then be calculated using elliptic integrals.Comment: 10 pages, 3 figures, LaTex. Typos corrected. References added. Accepted in Rad. Phys. Che

Analytical calculation of the solid angle defined by a cylindrical detector and a point cosine source with orthogonal axes

We derive analytical expressions for the solid angle subtended by a right circular cylinder at a point source with cosine angular distribution in the case where the source and the cylinder axes are mutually orthogonal.Comment: 19 pages, 13 figures, Latex. Typos corrected. Accepted in Rad. Phys. Che

Understanding basic numbers : examples from Brexit, Covid and common medical conditions

The UK Brexit debate and the current Covid pandemic have been fertile grounds for people seeking poor use of statistics, and demonstrate a need to reiterate some basic principles of data presentation. Communicating basic numbers to convey the correct message is a vital skill for a public health professional but even basic numbers can be difficult to understand, and are susceptible to misuse. The first issue is how to understand ‘orphan’ numbers; numbers quoted without comparison or context. This leads on to the problems of understanding numbers as proportions and how to make comparisons using proportions. Percentages, and in particular percentage changes, are also a major source of misunderstanding and the baseline percentage should always be given. The use of relative risk can also convey the wrong message and should always be accompanied by a measure of absolute risk. Similarly, numbers needed to treat should also refer to baseline risks. Communicating numbers is often more effective using natural counts or frequencies rather than fractions or proportions, and using pictorial representations of proportions can also be effective. The paper will also examine the problems of using simple ratios to try and adjust one continuous variable by another in particular the use of the BMI and for standardising death rates by institution. The misuse of reporting occurs in primary sources such as academic papers, but even more so in secondary reporting sources such as general media reports. It is natural to try and convey complex messages using a single summary number, but there are assumptions behind these summaries that should be questioned. It is usually better to give the individual numbers rather than a ratio of them

The use of a cephalonium containing dry cow therapy and an internal teat sealant, both alone and in combination

AbstractThe dry period is a critical time in the lactation cycle, being the optimum time to cure existing intramammary infection (IMI) as well as encompassing the periods of highest susceptibility to new infection. Currently, IMI in the dry period is controlled with antibiotic dry cow therapy. The aim of this randomized control trial was to investigate different dry cow therapy regimens by stratifying cows by likely infection status at drying off in herds with low somatic cell count (SCC; bulk milk SCC <250,000 cells/mL) in southwest England. All quarters in 890 cows were recruited. The recruited cows were categorized as either infected or uninfected on the basis of SCC and clinical mastitis history. Ipsilateral quarters within each cow were randomly allocated to receive 1 of 4 different treatment regimens according to their infection category. Quarters in high-SCC infected cows were allocated to receive antibiotic dry cow therapy either alone or in combination with an internal teat sealant; quarters in low-SCC uninfected cows were allocated to receive teat sealant either alone or in combination with antibiotic dry cow therapy. All quarters were sampled for bacteriology at drying off and again within 10 d post-calving. Quarters were subsequently monitored for clinical mastitis for the first 100 d of lactation. The mass of residual sealant was assessed immediately post-calving to allow assessment of the association of sealant retention with treatment efficacy. Models were constructed to assess the efficacy of the different regimens in preventing IMI. Apparent cure rates of existing IMI with major pathogens were consistently >90% in quarters receiving antibiotic. Combination treatment of high-SCC infected cows resulted in an increased likelihood of being pathogen free post-calving (odds ratio=1.40; 95% credibility interval=1.03–1.90). The benefits of combination treatment of low-SCC uninfected cows were less clear. With respect to clinical mastitis, combination treatment of high-SCC infected cows resulted in a decreased likelihood of developing clinical mastitis in the first 100 d of the subsequent lactation (odds ratio=0.68; 95% credibility interval=0.48–0.98). The retention of the internal sealant was adversely affected by its use in combination with antibiotic dry cow therapy

A Non-Relativistic Weyl Anomaly

We examine the Weyl anomaly for a four-dimensional z=3 Lifshitz scalar coupled to Horava's theory of anisotropic gravity. We find a one-loop break-down of scale-invariance at second order in the gravitational background.Comment: LaTeX, 23 pages, no figures, JHEP style; v2: typos fixed to match the published versio

An algorithm to describe the solution set of any tropical linear system A x=B x

An algorithm to give an explicit description of all the solutions to any tropical linear system A x=B x is presented. The given system is converted into a finite (rather small) number p of pairs (S,T) of classical linear systems: a system S of equations and a system T of inequalities. The notion, introduced here, that makes p small, is called compatibility. The particular feature of both S and T is that each item (equation or inequality) is bivariate, i.e., it involves exactly two variables; one variable with coefficient 1 and the other one with -1. S is solved by Gaussian elimination. We explain how to solve T by a method similar to Gaussian elimination. To achieve this, we introduce the notion of sub-special matrix. The procedure applied to T is, therefore, called sub-specialization