The importance of collegiality and reciprocal learning in the professional development of beginning teachers

This paper discusses factors which enhance induction experiences for beginning teachers. It reports the findings from case studies which explore the impact of new entrants to the teaching profession in Scotland. The data suggest that the most supportive induction processes mix both formal and informal elements, but that the informal elements such as collegiality, good communication and a welcoming workplace environment should not be underestimated. The study also highlights the potential benefits of a more collegiate environment for teachers across the career phases. Experienced teachers and new entrants had a range of experience to offer each other, thus creating more cohesive professional working which was supportive of early career teachers while encouraging reflection on practice among the more experienced professionals

Biennial Report: Everglades Drainage District Engineering Department 1925-1926

Report on Everglades drainage and other engineering projects 1925-1926, published 192

Everglades Drainage District: Biennial Report 1927-1928 to the Board of Commissioners of Everglades Drainage District

Everglades Drainage District report 1927-192

Generation of maximally entangled states with sub-luminal Lorentz boost

Recent work has studied entanglement between the spin and momentum components of a single spin-1/2 particle and showed that maximal entanglement is obtained only when boosts approach the speed of light. Here we extend the boost scenario to general geometries and show that, intriguingly, maximal entanglement can be achieved with boosts less than the speed of light. Boosts approaching the speed of light may even decrease entanglement. We also provide a geometric explanation for this behavior

The structure and components of European estuarine fish assemblages

This paper discusses the structure of fish assemblages using information from 17 European estuarine areas (in the British Isles, Portugal, Belgium, France, the Netherlands, Germany, Norway and Spain). Binary (presence/absence) and quantitative data for each assemblage have been used to assess the assemblage structure according to taxonomy (i.e. species identity). Following this, a total of 29 functional guilds were created in order to describe the use made of an estuarine area for each taxon encountered: feeding preferences, reproduction type, substratum preferences (for bottom dwelling fish) and position within the water column (vertical preference guild). The paper focuses on the designation and determination of the proportions of the guild members of the fish assemblage within each estuary. Ecological guilds within the assemblage include estuarine residents, marine juvenile migrants, catadromous and anadromous migrants, marine seasonal users, and freshwater and marine adventitious species. Feeding guilds include detritivores, planktonic feeders, infaunal croppers and sediment ingesters, piscivores, and active predators of mobile crustaceans. Reproduction guilds include planktonic and demersal spawners and those using brood-protection. The substratum preference indicates the proportions of sand, mud, rock and vegetation dwellers, and the vertical preference denotes benthic, demersal or pelagic species. The analysis has allowed both the estuaries to be grouped according to taxonomic and guild similarity and the characterisation of a typical European estuarine fish assemblage. Within the limits posed by differing sampling methods, times of sampling and survey rationale, there is a high similarity between estuaries. The data indicate common patterns of estuarine usage irrespective of the differences between the estuaries although such patterns cannot be interpreted fully given the incomplete knowledge of their physical and anthropogenic characteristics

Activity Dependent Branching Ratios in Stocks, Solar X-ray Flux, and the Bak-Tang-Wiesenfeld Sandpile Model

We define an activity dependent branching ratio that allows comparison of different time series $X_{t}$. The branching ratio $b_x$ is defined as $b_x= E[\xi_x/x]$. The random variable $\xi_x$ is the value of the next signal given that the previous one is equal to $x$, so $\xi_x=\{X_{t+1}|X_t=x\}$. If $b_x>1$, the process is on average supercritical when the signal is equal to $x$, while if $b_x<1$, it is subcritical. For stock prices we find $b_x=1$ within statistical uncertainty, for all $x$, consistent with an ``efficient market hypothesis''. For stock volumes, solar X-ray flux intensities, and the Bak-Tang-Wiesenfeld (BTW) sandpile model, $b_x$ is supercritical for small values of activity and subcritical for the largest ones, indicating a tendency to return to a typical value. For stock volumes this tendency has an approximate power law behavior. For solar X-ray flux and the BTW model, there is a broad regime of activity where $b_x \simeq 1$, which we interpret as an indicator of critical behavior. This is true despite different underlying probability distributions for $X_t$, and for $\xi_x$. For the BTW model the distribution of $\xi_x$ is Gaussian, for $x$ sufficiently larger than one, and its variance grows linearly with $x$. Hence, the activity in the BTW model obeys a central limit theorem when sampling over past histories. The broad region of activity where $b_x$ is close to one disappears once bulk dissipation is introduced in the BTW model -- supporting our hypothesis that it is an indicator of criticality.Comment: 7 pages, 11 figure

Weak Magnetism in Two Neutrino Double Beta Decay

We have extended the formalism for the two-neutrino double beta decay by including the weak-magnetism term, as well as other second-forbidden corrections. The weak magnetism diminishes the calculated half-lives in $\sim 10$, independently of the nuclear structure. Numerical computations were performed within the pn-QRPA, for $^{76}Ge$, $^{82}Se$, $^{100} Mo$, $^{128}Te$ and $^{130}Te$ nuclei. No one of the second-forbidden corrections modifies significantly the spectrum shapes. The total reduction in the calculated half lives varies from 6% up to 32%, and strongly depend on the nuclear interaction in the particle-particle $S=1,T=0$ channel. We conclude that the higher order effects in the weak Hamiltonian would hardly be observed in the two-neutrino double beta experiments.Comment: 8 pages, latex, 1ps figure, to appear in Phys. Lett.

Scintillation Caustics in Planetary Occultation Light Curves

We revisit the GSC5249-01240 light curve obtained during its occultation by Saturn's North polar region. In addition to refractive scintillations, the power spectrum of intensity fluctuations shows an enhancement of power between refractive and diffractive regimes. We identify this excess power as due to high amplitude spikes in the light curve and suggest that these spikes are due to caustics associated with ray crossing situations. The flux variation in individual spikes follows the expected caustic behavior, including diffraction fringes which we have observed for the first time in a planetary occultation light curve. The presence of caustics in scintillation light curves require an inner scale cut off to the power spectrum of underlying density fluctuations associated with turbulence. Another possibility is the presence of gravity waves in the atmosphere. While occultation light curves previously showed the existence of refractive scintillations, a combination of small projected stellar size and a low relative velocity during the event have allowed us to identify caustics in this occultation. This has led us to re-examine previous data sets, in which we have also found likely examples of caustics.Comment: 4 pages, 3 figures; ApJL submitte