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Bio‐optical properties of marine phytoplankton retrieved through satellite remote sensing are used to estimate ocean productivity and carbon cycling. Daily activity of phytoplankton is attuned to the predictable light fluctuations of the diel cycle. Field and laboratory studies have documented diel changes in phytoplankton growth, division, and respiration, carbon and pigment content, cell size, photosynthetic efficiency and rate, and DNA replication and transcription. Many of these physiological changes can alter cellular optical properties and contribute to diel variations in bulk absorption and scattering properties. Consequently, understanding phytoplankton contributions to diel optical cycles is essential for improving algorithms that convert remote sensing data to biological rates and stocks. Here, we describe time‐resolved cellular, photophysiological, and bio‐optical properties for three cultured phytoplankton ranging in cell size from ~ 1 to 6 μm: Ostreococcus lucimarinus, Synechococcus (WH8102), and Thalassiosira pseudonana, all of which can significantly contribute to phytoplankton abundance and/or biomass in the open and coastal ocean. This work is the first to characterize complete diel cycles in absorption and attenuation for O. lucimarinus and backscattering for all these species. Results show that the percent increase from the minimum to maximum values over the diel cycle ranged between ~ 24–121%, ~ 31–235%, and ~ 25–198% for particulate absorption, attenuation, and backscattering, respectively. Diel changes in bio‐optical properties also differed in both timing and magnitude across phytoplankton species, demonstrating the importance of contextualizing remote sensing observations with phytoplankton community composition. [ABSTRACT FROM AUTHOR]

The abundance and productivity of phytoplankton constrain energy transfer through marine food webs and the export of organic carbon to the deep ocean. Bio‐optical measurements correlate well with phytoplankton carbon (Cphyto), but the effect of taxonomic variability on this relationship is still uncertain. Here, we explore how changes in phytoplankton community composition influence the relationship between the particulate backscatter coefficient (bbp) and Cphyto and present a new approach to estimate phytoplankton biomass more accurately using bbp. We found that using a fixed scaling factor for the conversion of bbp to Cphyto could lead to the underestimation or overestimation of biomass, depending on the dominant taxonomic group in the phytoplankton community. In addition, we demonstrate how a simple ratio of absorption at two wavelengths can be used to provide a coarse approximation of phytoplankton community composition when scaling bbp to Cphyto, thereby improving the estimation of net primary production. [ABSTRACT FROM AUTHOR]

Summary: Plants and phytoplankton are natural sources of the volatile organic compounds (VOCs) acetone and isoprene, which are reactive and can alter atmospheric chemistry. In earlier research we reported that, when co‐cultured with a diatom, the marine bacterium Pelagibacter (strain HTCC1062; 'SAR11 clade') reduced the concentration of compounds tentatively identified as acetone and isoprene. In this study, experiments with Pelagibacter monocultures confirmed that these cells are capable of metabolizing acetone and isoprene at rates similar to bacterial communities in seawater and high enough to consume substantial fractions of the total marine acetone and isoprene budgets if extrapolated to global SAR11 populations. Homologues of an acetone/cyclohexanone monooxygenase were identified in the HTCC1062 genome and in the genomes of a wide variety of other abundant marine taxa, and were expressed at substantial levels (c. 10−4 of transcripts) across TARA oceans metatranscriptomes from ocean surface samples. The HTCC1062 genome lacks the canonical isoprene degradation pathway, suggesting an unknown alternative biochemical pathway is used by these cells for isoprene uptake. Fosmidomycin, an inhibitor of bacterial isoprenoid biosynthesis, blocked HTCC1062 growth, but the cells were rescued when isoprene was added to the culture, indicating SAR11 cells may be capable of synthesizing isoprenoid compounds from exogenous isoprene. [ABSTRACT FROM AUTHOR]

Diatoms are the most recent major algal lineage added to the geological record, appearing more than 200 million years ago. They are stramenopile protists resulting from a secondary endosymbiotic event that yielded the only photosynthetic protistan lineage expressing external siliceous cell wall structures called frustules. Many diatoms also have large internal vacuoles, and a common assumption in the literature is that success of the diatoms is largely attributable to these two morphological inventions: the frustule for defense and vacuole for luxury nutrient uptake. Here, we revisit the evolution of these inventions, propose sequential steps in frustule development, replace luxury nutrient uptake with predator defense and buoyancy control as the driver of vacuole expansion, and suggest that perhaps the greatest significance of the frustule for diatom evolution is the secondary consequence of enhancing sexual reproduction. In this synthesis, we emphasize a distinction between the "general" success of diatoms and the success of "bloom‐forming" species, as the physiological and morphological drivers of these successes differ. Importantly, the bloom‐forming species are responsible for the major role of diatoms in aquatic biogeochemical cycles. The bloom‐forming habit we ascribe to specific physiological attributes that, at their core, revolve around influencing the balance between diatom growth and losses to predators. We propose that these physiological adaptations are linked to size‐dependent maximum division rates in bloom‐forming diatoms, because of size scaling of predator–prey interactions. The existence of these bloom‐forming species yields an apparent allometric relationship that has previously been interpreted in terms of nutrient acquisition. Our analysis yields insights into species successions during blooms, considers the fundamental benefit of blooming (and subsequent sinking) from a reproductive standpoint, and provides some reinterpretation of diatoms success over geologic time and in the modern ocean. [ABSTRACT FROM AUTHOR]

Episodic deep mixing events are one component of the biological carbon pump that physically transports organic carbon into the mesopelagic. Episodic deep mixing also disrupts summertime thermal stratification thereby changing the light field and nutrient concentrations available for phytoplankton growth. Phytoplankton survival and growth below the mixed layer following restratification depends on how rapidly cells can employ a variety of photoacclimation processes in response to the environmental changes. To compare the relative timescales of summertime episodic deep mixing events with the timescales of phytoplankton photoacclimation processes, we first analyzed autonomous float data to survey the frequency and magnitude of deep mixing events in the western North Atlantic Ocean. Next, we simulated a sustained deep mixing event in the laboratory and measured rates of acclimation processes ranging from light harvesting to growth in a model diatom and green alga. In both algae increases in chlorophyll (Chl) were coupled to growth, but growth of the green alga lagged the diatom by about a day. In float profiles, significant increases in Chl and phytoplankton carbon (Cphyto) were detected below the mixed layer following episodic deep mixing events. These events pose a previously unrecognized source of new production below the mixed layer that can significantly boost the amount of carbon available for export to the deep ocean. [ABSTRACT FROM AUTHOR]

The 14C incubation method for net primary production (NPP) has limited spatial/temporal resolution, while satellite approaches cannot provide direct information at depth. With chlorophyll‐a and backscatter measurements from BGC‐Argo floats, we quantified year‐round NPP in the western North Atlantic Ocean using both the Carbon‐based Productivity Model (CbPM) and Photoacclimation Productivity Model (PPM). Comparison with NPP profiles from 14C incubation measurements showed advantages and limitations of both models. CbPM reproduced the magnitude of NPP in most cases. However, in the summer the CbPM‐based NPP had a large peak in the subsurface, which was an artifact from the subsurface chlorophyll maximum caused by photoacclimation. PPM avoided the artifacts from photoacclimation, but the magnitude of PPM‐derived NPP was smaller than the 14C result. Different NPP distribution patterns along a North‐South transect in the Western North Atlantic Ocean were observed, including higher winter NPP/lower summer NPP in the south, timing differences in NPP seasonal phenology, and different NPP depth distribution patterns in the summer months. Using a 6‐months record of concurrent oxygen and bio‐optical measurements from two Argo floats, we also demonstrated the ability of Argo floats to obtain estimates of the net community production to NPP ratio, ranging from 0.3 in July to −1.0 in December 2016. Our results highlight the utility of float bio‐optical profiles and indicate that environmental conditions (e.g., light availability, nutrient supply) are major factors controlling the seasonality and spatial (horizontal and vertical) distributions of NPP in the western North Atlantic Ocean. Key Points: Net primary production (NPP) derived from Argo‐based bio‐optical measurements was comparable and complementary to 14C incubation and satellite estimatesBoth Carbon‐based Productivity Model and Photoacclimation Productivity Model have their own advantages and limitationsNPP profiles showed varying seasonal NPP distribution patterns along a North‐South transect in the western North Atlantic Ocean [ABSTRACT FROM AUTHOR]

Summary: Volatile organic compounds (VOCs) produced by phytoplankton are molecules with high vapor pressures that can diffuse across cell membranes into the environment, where they become public goods. VOCs likely comprise a significant component of the marine dissolved organic carbon (DOC) pool utilized by microorganisms, but they are often overlooked as growth substrates because their diffusivity imposes analytical challenges. The roles of VOCs in the growth of the photoautotrophic diatom Thalassiosira pseudonana and heterotrophic bacterium Pelagibacter sp. HTCC1062 (SAR11) were examined using co‐cultures and proton‐transfer reaction time‐of‐flight mass spectrometry. VOCs at 82 m/z values were produced in the cultures, and the concentrations of 9 of these m/z values changed in co‐culture relative to the diatom monoculture. Several of the m/z values were putatively identified, and their metabolism by HTCC1062 was confirmed by measuring ATP production. Diatom carbon fixation rates in co‐culture with HTCC1062 were 20.3% higher than the diatom monoculture. Removal of VOCs from the T. pseudonana monoculture using a hydrocarbon trap caused a similar increase in carbon fixation (18.1%). These results show that a wide range of VOCs are cycled in the environment, and the flux of VOCs from phytoplankton to bacterioplankton imposes a large and unexpected tax on phytoplankton photosynthesis. [ABSTRACT FROM AUTHOR]

Acetaldehyde, methanol, acetone, and isoprene are important reactive volatile organic compounds (VOCs) in the oceans that partition to the atmosphere in significant amounts. Reports of potentially high rates of VOC turnover in the North Atlantic suggested that both biotic and abiotic processes are involved. The biological basis for VOC cycling by ocean plankton is unknown, but is potentially important because of VOC contributions to carbon cycle budgets and atmospheric chemistry. We designed dynamic stripping chambers that coupled to a proton transfer reaction mass spectrometer to measure VOC production and consumption by cultured phytoplankton and bacterioplankton. The diatom, Thalassiosira pseudonana, produced acetaldehyde in a light-dependent manner. Acetaldehyde was oxidized by the chemoheterotrophic bacterium, Pelagibacter, at rates that suggest that most acetaldehyde is recycled in the ocean before escaping to the atmosphere. These results show that field observations of acetaldehyde turnover reported previously could be explained by biological activity. Rates of production by phytoplankton cultures of methanol, acetone, and isoprene were also measured. These findings support the conclusion that VOCs are a conduit for carbon transfer directly from phytoplankton to bacterioplankton, with the remainder available for escape to the atmosphere. [ABSTRACT FROM AUTHOR]

Recent advances in sorting flow cytometry (SFCM) and sensitive biochemical techniques have opened the door for a variety of new incubation-free measurements to assess cell physiology. We adapted highly sensitive bioluminescent methodologies to measure cell NAD(H) and adenosine triphosphate (ATP) contents as predictors of phytoplankton primary production and growth rate. We first applied these methods to algae in taxonomically distinct groups: the chlorophyte Dunaliella tertiolecta, the diatom Thalassiosira pseudonana and a model cyanobacterium Synechococcus sp. WH8102. We found that NAD(H) content [NAD(H)phyto] increased significantly with increasing net primary productivity (NPP) and growth rate. In contrast, and in agreement with previous studies, phytoplankton ATP content (ATPphyto) was highly correlated with carbon biomass. Furthermore, ATPphyto was not correlated with NPP or growth rate. As a field test of the method, we then measured NAD(H)phyto in phytoplankton samples collected by SFCM in the North Pacific. These measurements yielded an estimate of NPP closely matching that from the traditional incubation-dependent 14C uptake technique. The methods described here enable low-biomass, incubation-free estimates of phytoplankton NPP, growth rate, and biomass. [ABSTRACT FROM AUTHOR]

The Carbon, Absorption, and Fluorescence Euphotic-resolving (CAFE) net primary production model is an adaptable framework for advancing global ocean productivity assessments by exploiting state-of-the-art satellite ocean color analyses and addressing key physiological and ecological attributes of phytoplankton. Here we present the first implementation of the CAFE model that incorporates inherent optical properties derived from ocean color measurements into a mechanistic and accurate model of phytoplankton growth rates ( μ) and net phytoplankton production (NPP). The CAFE model calculates NPP as the product of energy absorption ( QPAR), and the efficiency ( ϕ μ) by which absorbed energy is converted into carbon biomass ( CPhyto), while μ is calculated as NPP normalized to CPhyto. The CAFE model performance is evaluated alongside 21 other NPP models against a spatially robust and globally representative set of direct NPP measurements. This analysis demonstrates that the CAFE model explains the greatest amount of variance and has the lowest model bias relative to other NPP models analyzed with this data set. Global oceanic NPP from the CAFE model (52 Pg C m−2 yr−1) and mean division rates (0.34 day−1) are derived from climatological satellite data (2002-2014). This manuscript discusses and validates individual CAFE model parameters (e.g., QPAR and ϕ μ), provides detailed sensitivity analyses, and compares the CAFE model results and parameterization to other widely cited models. [ABSTRACT FROM AUTHOR]

Lymphangiosarcomas are uncommon vascular neoplasms that arise from lymphatic endothelial cells (LECs). They efface and replace normal subcutaneous tissue and are characterised by arborising, vascular channels lined by a single layer of pleomorphic endothelial cells and a paucity of erythrocytes. Lymphangiosarcomas are architecturally similar to hemangiosarcomas, a common malignancy of vascular origin arising from blood vascular endothelial cells. Common immunohistochemical markers for vascular endothelium, such as Factor VIII-related antigen (F8RA) and CD31, have traditionally been used to confirm the diagnosis of tumours of vascular origin. However, these markers fail to differentiate between lymphangiosarcoma and hemangiosarcoma, which often show overlapping morphologic features, disparate clinical behaviour and require different treatment modalities. Here we describe the use of two novel LEC-specific markers, lymphatic vessel endothelial receptor-1 ( LYVE-1) and prospero-related homeobox gene-1 ( PROX-1), to further differentiate between vascular tumours of lymphatic (lymphangiosarcoma) and blood (hemangiosarcoma) endothelial cell origin in the dog. [ABSTRACT FROM AUTHOR]

Lymphangiosarcoma ( LAS) is an uncommon malignant neoplasia arising from lymphatic endothelium; little information exists regarding therapy. Single institutional retrospective review for canine LAS histopathology diagnoses over a 15-year period yielded 12 dogs. Ten dogs were presented for a mass and/or swelling at cervical, trunk or limb regions. Prior to diagnosis, 10 dogs received empiric wound therapy. Cytology performed in 10 consisted of mild inflammation. Survival ranged from 60, 168 and 876 days for three dogs with palliation; 90 days with prednisone in one; 182 days with chemotherapy in one; 240, 267, 487, 630 and 941 days for five receiving surgery; and 574 days for one receiving surgery, radiation and chemotherapy. One dog is alive with recurrence at 243 days following surgery and carboplatin chemotherapy. Clinical improvement existed in LAS dogs receiving multimodal therapies. Early tissue biopsies are recommended for progressive oedematous lesions of unknown origin. [ABSTRACT FROM AUTHOR]

We compare the nutrient-dependent photosynthetic efficiencies of the chlorophyte, Dunaliella tertiolecta, with those of the marine diatom, Thalassiosira weissflogii. Despite considerable evolutionary and physiological differences, these two species appear to use nearly identical growth strategies under a wide range of nutrient limitation., Using a variety of physiological measurements, we find that, for both species and across all growth rates, 75% of the gross photosynthetic electron flow is invested in carbon fixation and only 30% is retained as net carbon accumulation. A majority of gross photosynthesis (70%) is ultimately used as reductant for biosynthetic pathways and for the generation of ATP., In both species, newly formed carbon products exhibit much shorter half-lives at slow growth rates than at fast growth rates. We show that this growth rate dependence is a result of increased polysaccharide storage during the S phase of the cell cycle., We present a model of carbon utilization that incorporates this growth rate-dependent carbon allocation and accurately captures ( r2 = 0.94) the observed time-resolved carbon retention. Together, our findings suggest a common photosynthetic optimization strategy in evolutionarily distinct phytoplankton species and contribute towards a systems-level understanding of carbon flow in photoautotrophs. [ABSTRACT FROM AUTHOR]

Summary The 1.3 Mbp genome of HTCC2181, a member of the abundant OM43 clade of coastal bacterioplankton, suggested it is an obligate methylotroph. Preliminary experiments demonstrated that methanol and formaldehyde, but not other common C1 compounds such as methylamine, could support growth. Methanol concentrations in seawater are reportedly < 100 nM, suggesting either that the flux of methanol through plankton pools is very rapid, or that methanol may not be the primary growth substrate for HTCC2181. Therefore, we investigated the apparent extreme substrate range restriction of HTCC2181 in greater detail. Growth rate and maximum cell density of HTCC2181 increased with methanol concentration, yielding a Ks value of 19 µM. In contrast, no growth was observed in the presence of the methylated (C1) compounds, methyl chloride, trimethylamine-oxide (TMAO) or dimethylsulfoniopropionate (DMSP) when they were the sole substrates. However, growth rate, maximum cell density and cellular ATP content were significantly enhanced when any of these methylated compounds were provided in the presence of a limiting concentration of methanol. These observations fit a model in which the metabolic intermediate formaldehyde is required for net carbon assimilation, allowing C1 substrates that do not produce a formaldehyde intermediate to be oxidized for energy, but not assimilated into biomass. Rates of methanol and TMAO oxidation and assimilation were measured with 14C-radiolabelled compounds in cultures of HTCC2181 and seawater microbial communities collected off the Oregon coast. The results indicated that in nature as well as in culture, C1 substrates are partitioned between those that are mainly oxidized to produce energy and those that are assimilated. These findings indicate that the combined fluxes of C1 compounds in coastal systems are sufficient to support significant populations of obligate methyltrophs by a metabolic strategy that involves the synergistic metabolism of multiple C1 compounds. [ABSTRACT FROM AUTHOR]

Intracranial hemangioma is a rare intraaxial hemorrhagic neoplasm with imaging characteristics similar to other intracranial hemorrhagic lesions. We describe two canine cerebral hemangiomas that appeared as poorly circumscribed intraaxial compressive lesions that were predominantly hypointense on T2 sequences and heterogeneously contrast enhancing. Both lesions had perilesional edema and were hypointense on T2-gradient recalled echo sequences, consistent with hemorrhage. In one tumor a short partial peripheral rim was present, which was suggestive of hemosiderin deposition. Cerebral hemangioma should be included as a differential for hemorrhagic intracranial lesions. [ABSTRACT FROM AUTHOR]

The chl-specific short-term C-based production ( P) measurement is a widely used tool to understand phytoplankton responses to environmental stresses. However, among the metabolic consequences of these stresses is variability in lifetimes of newly fixed carbon that cause P to range between chl-specific net primary production ( NPP *) and chl-specific gross photosynthetic electron flow that is available for carbon reduction () depending on growth rate. To investigate the basis for this discrepancy, photosynthate utilization was characterized in Dunaliella tertiolecta Butcher grown at three different growth rates in N-limited chemostats. P was measured throughout a 2 min to 24 h time course and showed clear growth-rate-dependent differences in lifetimes of newly fixed carbon. C pulse-chase experiments revealed differences in patterns of carbon utilization between growth rates. At high growth rate, the majority of C was initially fixed into polysaccharide and lipid, but the relative contribution of each labeled biochemical pool to the total label changed over 24 h. In fast-growing cells, labeled polysaccharides decreased 50%, while labeled lipids increased over the first 4 h. At low growth rate, C was initially incorporated primarily into protein, but the contribution of labeled protein to the total label increased over the next 24 h. Together, time-resolved measurements of P and cellular NAD and NADP content suggest an enhanced role for alternative dissipation pathways at very low growth rate. Findings of this study contribute to an integrated understanding of growth-rate-dependent shifts in metabolic processes from photosynthesis to net growth. [ABSTRACT FROM AUTHOR]

This case series presents a unique and unreported variant of feline intestinal mast cell tumour recognized at the CSU Veterinary Diagnostic Laboratory. Fifty cases of feline intestinal mast cell tumours described as having a significant stromal component were reviewed. Neoplastic cells formed a trabecular pattern admixed with moderate to abundant dense stromal collagen (sclerosis). Neoplastic cells had poorly discernible intracytoplasmic granules which demonstrated metachromasia with special histochemical stains consistent with mast cell granules. Additionally, a subset of cases stained for mast cell-specific tryptase and c-kit demonstrated positive immunoreactivity. Eosinophilic infiltrates were moderate to marked in almost all cases. Lymph node and hepatic metastases were present in 66% of the cases. Treatment and clinical outcome was available in 25/50 cases. Twenty-three of these patients died or were euthanized within 2 months of initial diagnosis. This is the first case series to characterize a sclerosing variant of intestinal mast cell tumour in the cat which appears to have a high propensity for metastasis and a guarded prognosis. [ABSTRACT FROM AUTHOR]

High-throughput mRNA differential display (DD) was used to identify genes induced by cyclohexane inBrachymonas petroleovoransCHX, a recently isolatedβ-proteobacterium that grows on cyclohexane. Two metabolic gene clusters were identified multiple times in independent reverse transcription polymerase chain reactions (RT-PCR) in the course of this DD experiment. These clusters encode genes believed to be required for cyclohexane metabolism. One gene cluster (8 kb) encodes the subunits of a multicomponent hydroxylase related to the soluble butane ofPseudomonas butanovoraand methane monooxygenases (sMMO) of methanotrophs. We propose that this butane monooxygenase homologue carries out the oxidation of cyclohexane into cyclohexanol during growth. A second gene cluster (11 kb) contains almost all the genes required for the oxidation of cyclohexanol to adipic acid. Real-time PCR experiments confirmed that genes from both clusters are induced by cyclohexane. The role of the Baeyer–Villiger cyclohexanone monooxygenase of the second cluster was confirmed by heterologous expression inEscherichia coli. [ABSTRACT FROM AUTHOR]

This paper advances the position that sociology needs to develop an approach to research which focuses on fundamental social problems. In doing so it shares many of the intellectual values and goals of political arithmetic while seeking to move methodologically beyond it. Since such problems are complex they will require, typically, interdisciplinary input and a concomitant approach to the development and appraisal of theories. We are not, therefore, advocating the primacy of sociology but arguing that it has a distinctive part to play in addressing the fundamental problems of the twenty-first century. However, a policy-oriented sociology has also to take up the task, so clearly defined by the tradition of political arithmetic, which is to hold governments to account. Consequently a central principle of a new policy science is that it should contribute to democratic debate about policy. [ABSTRACT FROM AUTHOR]

The article aims to understand the meaning of the inaugural address, The Application of Social Research, given by sociologist David Glass in order to reassert the potential of sociology as political arithmetic, to comment on progress or the lack of it, since he died in 1978, and to illustrate from the example of British higher education just as Glass did for urban planning at that time. The contemporary search for improved accountability derives more or less from the world of innocence in which, after World War II, Glass gave his inaugural address and the Welfare State was born. It was a world of common consensual goals. By general consent, a world fit for heroes and cripples was to be created, giving civilized substance to peace and justifying the sacrifices of war. Guaranteed public provision of health, education, and welfare were agreed as aims, and the means were thought possible. In Britain this meant a benign state, an uncorrupt bureaucracy and public-spirited professions. Government enjoyed remarkable credence. Political democracy rested on enthusiastic support, and belief was widespread that the will of the majority could be translated faithfully through the chain of democracy from the electorate through Parliament to the executive, and finally, to action.

This articles provides an overview of the topics on British sociology discussed in the September 1989 issue of The British Journal of Sociology. Pahl and Westergaard's reports to the University Grants Council on the institutional state of sociology in the British universities, represents a sociography of the sociological establishment at the last moment of a constitution of more or less autonomous universities which is not to pass to national management by the Universities' Funding Council. While Albrow's view of the nature of sociology offers illuminating contrast with the view taken by W. G. Runciman. Runciman dismissed some other fashionable explanations and went on to put forward his own terms of the nature of the subject. The significance of education in the political economy of modern society differs sharply in liberal and Marxist theory. For liberal it is central to the determination of both production and distribution. For Marxists it is a dependent variable about which Marx himself wrote little. In more recent writing the contrast continues, mainly because of opposed interpretations of the changes in the structure of employment and the incidence of the changes in the structure of employment and the incidence of social mobility both of which entail theories of the relation between education and employment.

This article presents the question of social class differences in measured intelligence as an illustration of the more general problem of the relation between social structure and the distribution of genetic characteristics in populations. Though innate intelligence may legitimately be inferred from available evidence, the evidence is also strong that it is determined not by one gene but polygenically. On these assumptions a genetic model may be constructed which, when relevant variations in social structure are taken into account, throws considerable doubt on the possibility that mean differences between classes in measured intelligence are innate. When a caste society is transformed into a class society the classes, may still be seen as gene pools but with migration between them. The question now becomes one of determining the relation between social mobility and genic migration. On the evidence, especially of correlation coefficients derived from studies of twins, siblings and foster children, it may be concluded that there is a genetic component in the intelligence test performance of individuals.

This article analyzes the cohort of boys entering secondary schools in the Educational Division of South-West Hertfordshire in England 1952, 1953 and 1954. The occupations followed by the fathers of boys entering in 1952 were obtained by interview with their parents as part of the wider inquiry already referred to, and in the same connection the authority kindly supplied the intelligence quotient of the boys based on their performance in the Moray House 37 intelligence test, administered under their auspices as part of the selection procedure. With the co-operation of the Heads concerned, the same test was administered under our auspices in the schools to entrants in 1953 and 1954 and a brief statement of his father's occupation was obtained from each boy, so that the social and intellectual composition of the entry could be compared for these three years. The information as to the father's occupation in 1953 and 1954 was necessarily less reliable than in 1952 and the proportion of unclassifiable cases was higher. To ensure that any error in the analysis would be in the right direction, all doubtful or unclassifiable cases were added to the working-class group. The occupational classification used is a modification of that used by the Government Social Survey.

Material collected from 700 London secondary schoolboys suggests that, despite the changes introduced into secondary education by the Education Act of 1944, it remains the case that a boy has a greater chance of entering a Grammar School if he comes from a middle-class rather than a working-class home. The difference in social composition between Grammar and Modem Schools cannot be completely explained by reference to the crucial role played by intelligence tests in the selection procedure, for at the borderline range of intelligence the chances of allocation to a Grammar School are closely related to social class. Nor can the distribution of intelligence explain the greater proportion of boys from small families found in the Grammar Schools since only in the working-class group is this a distinguishing characteristic of Grammar as opposed to Modem School boys. It would seem rather that some of the factors which were known to reduce the chances of entry to a Grammar School as the holder of a free or special place still continue to exercise their effect. Success in the Grammar School itself follows the same pattern. Working-class children, especially those from large families, appear on the whole to fit less easily into the life of a Grammar School than boys from middle-class homes and smaller families. The length of school life preferred by the boy, and (according to him) by his parents, is shorter the lower his social level and the larger his family. Middle-class boys tend to have superior academic records despite the fact that, as a group, they do not differ in measured intelligence from working-class boys in the same school. The latter, especially those from larger families, seem to have less aspiration and parental pressure towards achievement. They tend to be rated by their masters on personality traits such as industriousness and sense of responsibility at a lower level than middleclass boys, and they confess less interest in extra-curricula activities organized by the school. The evidence would suggest that the middle-class boy rather than the working-class boy, and the boy from a small family rather than a large family is better equipped in his attitudes and family background to take full advantage of education in a Grammar School and thus to set out on a career leading to an occupation of high social prestige. [ABSTRACT FROM AUTHOR]

This article studies the views of adolescent boys on some aspects of the social class structure in England. Information was sought on the following topics: What meaning do young adolescents attach to the term social class? How many social classes do they think exist and how do they describe them? To what degree are they aware of certain outward symbols of social status, and how far does their prestige ranking of occupations resemble that of adults? It was found that 60 percent of the sample did not understand the concept of social class. The lower working-class boys tended to be least familiar with the term, a difference which further analysis showed to be independent of differences in intelligence. It was also found that boys, when ranking individuals along some kind of social status scale, referred to them as important or not so important.

The article presents a case study of a six-year-old male neutered Rhodesian Ridgeback with intracranial tumors. It notes that a strain in urination and defecation has resulted in inappetent and lethargic actions by the dog. It mentions that the tumor has been identified through magnetic resonance imaging (MRI).

A letter to the editor about idiopathic intracranial hypertension with papilledema is presented.