Essays on Biological Individuality

Much of biology, especially evolutionary theory, makes assumptions about the individuality of living things. A population, for example, is made up of individuals. Those individuals sometimes reproduce, creating new individuals. The very use of these concepts requires that living individuals can be distinguished both synchronically and diachronically. There are many examples in nature, however, in which a living system is present, but it is not clear how to understand that system's individuality. Plants, fungi, colonial marine invertebrates, insect colonies, and symbiosis are all classic cases that have puzzled biologists interested in understanding their population structure and evolution. Scientific exploration of these issues has connections with traditional philosophical terrain, particularly the ontology of persistence and the nature of individuality broadly construed. A biologically informed philosophical literature has arisen in recent years, aimed at understanding the nature of biological individuality and its role in biological theorizing. My dissertation makes two kinds of contributions to this current literature. One contribution is theoretical, reframing our thinking about biological individuality. I distinguish between two categories of individuality and argue that they play different roles in theorizing about nature. One important kind of individual is that of the organism, understood as an entity that persists through space and time, takes in and processes resources from the environment, and maintains physiological autonomy. Another important kind of individual is that of the evolutionary individual, understood as an entity that has the capacity to participate in processes of natural selection. Distinguishing between these two types of individuality has theoretical utility, keeping clear the distinctive kinds of biological processes that individuals engage in. The other contribution of my dissertation involves detailed natural historical analysis of three kinds of problem cases. Using the framework articulated earlier in the dissertation, I assess the individuality of symbioses between larger organisms and their microbial associates, mushroom-producing fungi, and the classic case of ant colonies. The combined result of the assessments is a hierarchical pluralism about biological individuality.Philosoph

Molecular Cloud Structure in the Magellanic Clouds: Effect of Metallicity

The chemical structure of neutral clouds in low metallicity environments is examined with particular emphasis on the H to H_2 and C+ to CO transitions. We observed near-IR H_2 lines and the CO J=1-0 line from 30 Doradus and N159/N160 in the Large Magellanic Cloud and from DEM S 16, DEM S 37, and LI-SMC 36 in the Small Magellanic Cloud. We find that the H_2 emission is UV-excited and that (weak) CO emission always exists (in our surveyed regions) toward positions where H_2 and [CII] emission have been detected. Using a PDR code and a radiative transfer code, we simulate the emission of line radiation from spherical clouds and from large planar clouds. Because the [CII] emission and H_2 emission arise on the surface of the cloud and the lines are optically thin, these lines are not affected by changes in the relative sizes of the neutral cloud and the CO bearing core, while the optically thick CO emission can be strongly affected. The sizes of clouds are estimated by measuring the deviation of CO emission strength from that predicted by a planar cloud model of a given size. The average cloud column density and therefore size increases as the metallicity decreases. Our result agrees with the photoionization regulated star formation theory by Mc Kee (1989).Comment: 45 Pages including 15 figures. To be published in the ApJ May 10, 1998 issue, Vol. 49

Influence of electronic correlations on the frequency-dependent hopping transport in Si:P

At low energy scales charge transport in the insulating Si:P is dominated by activated hopping between the localized donor electron states. Thus, theoretical models for a disordered system with electron-electron interaction are appropriate to interpret the electric conductivity spectra. With a newly developed technique we have measured the complex broadband microwave conductivity of Si:P from 100 MHz to 5 GHz in a broad range of phosphorus concentration $n/n_c$ from 0.56 to 0.95 relative to the critical value $n_c=3.5\times 10^{18}$ cm$^{-3}$ corresponding to the metal-insulator transition driven by doping. At our base temperature of $T =1.1$ K the samples are in the zero-phonon regime where they show a super-linear frequency dependence of the conductivity indicating the influence of the Coulomb gap in the density of the impurity states. At higher doping $n\to n_c$, an abrupt drop in the conductivity power law \sig(\omega)\sim\omega^\alpha is observed. The dielectric function \eps increases upon doping following a power law in ($1-n/n_c$). Dynamic response at elevated temperatures has also been investigated.Comment: 5 pages, 7 figures, conference "Transport in Interacting Disordered Systems" Marburg, August 6 - 10, 200

Ensuring an Essential Supply of Allied Health Professions (AHP) Placements: Using Crowdsourcing to Develop a National Call to Action

Sustainable growth in the Allied Health Professions (AHP) workforce is an ambition of the United Kingdom’s NHS Long Term Plan. However historically, access to good quality placements has been a barrier to increasing pre-registration training numbers. This article focuses on work carried out by Health Education England (HEE) to gain insights on the impact of the COVID-19 pandemic on capacity. Using a pragmatic, embedded mixed-methods approach, insights were gathered using an online workshop, crowdsourcing, open for two weeks in the summer of 2020. AHP placement stakeholders could vote, share ideas or comment. Descriptive data were extracted, and comments made were analysed using inductive thematic analysis. Participants (N = 1,800) made over 8,500 comments. The themes identified included: diversity of placement opportunity, improved placement coordination, a more joined-up system, supervision models and educator capacity. Alongside considering the challenges to placement capacity, several areas of innovative practice owing to the pandemic were highlighted. Generated insights have shaped the aims and objectives of the Health Education (HEE) pre-registration AHP student practice learning programme for 2020/2021 and beyond. The COVID-19 pandemic has disrupted the delivery of AHP placements. In the absence of face-to-face activities, crowdsourcing provided an online data collection tool offering stakeholders an opportunity to engage with the placement capacity agenda and share learning. Findings have shaped the HEE approach to short-term placement recovery and long-term growth

Machiavellianism, emotional manipulation, and friendship functions in women's friendships

Machiavellianism and emotional manipulation has not been investigated in friendships. The current studies investigated Machiavellianism, emotional manipulation, and six friendship functions in women's same-sex friendships. For study 1, women (N = 221) completed the Mach IV, emotional manipulation measure (with reference to their own behaviour and their friend's behaviour), mood worsening and use of inauthentic displays from the managing emotions of others scale, and the friendship function measure. Machiavellianism predicted the self-perceived ability to employ emotional manipulation towards a same-sex friend and perceiving their friend to use emotional manipulation towards them. Machiavellianism predicted lower scores on all six friendship functions. For study 2, women (N = 186) completed the Mach IV, the modified emotional manipulation measure (with reference to their own behaviour and their friend's behaviour), and the friendship function measure. Women high on Machiavellianism reported using emotional manipulation more frequently towards their same-sex friend and perceived their same-sex friend to frequently use emotional manipulation towards them. Machiavellianism predicted lower scores on five of the friendship functions. These studies demonstrated that women higher on Machiavellianism employ emotional manipulation in their same-sex friendships. Women with higher Machiavellianism scores also perceived that they themselves were manipulated by their friend

What is a hologenomic adaptation? Emergent individuality and inter-identity in multispecies systems

Contemporary biological research has suggested that some host–microbiome multispecies systems (referred to as “holobionts”) can in certain circumstances evolve as unique biological individual, thus being a unit of selection in evolution. If this is so, then it is arguably the case that some biological adaptations have evolved at the level of the multispecies system, what we call hologenomic adaptations. However, no research has yet been devoted to investigating their nature, or how these adaptations can be distinguished from adaptations at the species-level (genomic adaptations). In this paper, we cover this gap by investigating the nature of hologenomic adaptations. By drawing on the case of the evolution of sanguivory diet in vampire bats, we argue that a trait constitutes a hologenomic adaptation when its evolution can only be explained if the holobiont is considered the biological individual that manifests this adaptation, while the bacterial taxa that bear the trait are only opportunistic beneficiaries of it. We then use the philosophical notions of emergence and inter-identity to explain the nature of this form of individuality and argue why it is special of holobionts. Overall, our paper illustrates how the use of philosophical concepts can illuminate scientific discussions, in the trend of what has recently been called metaphysics of biology

Are autistic traits measured equivalently in individuals with and without an Autism Spectrum Disorder?:An invariance analysis of the Autism Spectrum Quotient Short Form

It is common to administer measures of autistic traits to those without autism spectrum disorders (ASDs) with, for example, the aim of understanding autistic personality characteristics in non-autistic individuals. Little research has examined the extent to which measures of autistic traits actually measure the same traits in the same way across those with and without an ASD. We addressed this question using a multi-group confirmatory factor invariance analysis of the Autism Quotient Short Form (AQ-S: Hoekstra et al. in J Autism Dev Disord 41(5):589-596, 2011) across those with (n = 148) and without (n = 168) ASD. Metric variance (equality of factor loadings), but not scalar invariance (equality of thresholds), held suggesting that the AQ-S measures the same latent traits in both groups, but with a bias in the manner in which trait levels are estimated. We, therefore, argue that the AQ-S can be used to investigate possible causes and consequences of autistic traits in both groups separately, but caution is due when combining or comparing levels of autistic traits across the two group

Evidence for the immobile bipolaron formation in the paramagnetic state of the magnetoresistive manganites

Recent research suggests that the charge carriers in the paramagnetic state of the magnetoresistive manganites are small polarons. Here we report studies of the oxygen-isotope effects on the intrinsic resistivity and thermoelectric power in several ferromagnetic manganites. The precise measurements of these isotope effects allow us to make a quantitative data analysis. Our results do not support a simple small-polaron model, but rather provide compelling evidence for the presence of small immobile bipolarons, i.e., pairs of small polarons. Since the bipolarons in the manganites are immobile, the present result alone appears not to give a positive support to the bipolaronic superconductivity theory for the copper-based perovskites.Comment: 6 pages, 5 figures, monor correction