The ideal long-term record: Using baleen to understand changes in whale feeding and spatial movements through time

The stable isotopes of nitrogen (δ15N) and carbon (δ13C) within whale baleen plates provide an indirect measure of individual resource use, migration strategy, and physiological changes at an interannual level. Predictable annual changes in whale dietary input and/or physiological condition (e.g., annual fasting periods) cause periodic oscillations in nitrogen and carbon stable isotope values within a baleen plate. However, there is a high degree of interannual variability in stable isotope oscillation patterns observed, both within an individual, as well as within and between populations, making interpretations difficult. This interannual variability may be driven by changes in resource utilisation, movements between different regions, and/or a difference in fasting endurance. However, methods to quantify variability in stable isotope patterns and what drives these differences each year remain unknown. In my thesis, I develop new methodology to quantify variability in baleen stable isotope patterns, and then applied these methods to examine some of the potential drivers behind baleen stable isotope variability. Overall, I show that large-scale climate cycles and oceanographic signals (like SST) are associated with changes in baleen stable isotope patterns. I also show, for some species, that baleen stable isotope patterns vary between males and females of the same species and thus, sex differences may also drive inter-individual variability within a population. Additionally, I infer the resource use and movement patterns of the smallest baleen whale, the pygmy right whale, commonly left out among comparisons with other baleen whale species. I find evidence to suggest they remain in temperate waters between southern Australia and the Subtropical Convergence, where they likely rely on euphausiid and copepod species to sustain their feeding and breeding requirements. Despite the lack of research on pygmy right whales, I show that their annual presence in coastal waters make them a relatively accessible species to study. Previously, the stable isotope patterns within baleen have been valuable in identifying feeding and movement patterns within individuals. However, the need to explore how these patterns relate to changes in the environment as well as meaningful ways to quantify interannual variability in stable isotope patterns (i.e., changes in resource use and movement strategies) will be essential forecasting tools within a changing climate

A Machine Learning Approach for Automated Fine-Tuning of Semiconductor Spin Qubits

While spin qubits based on gate-defined quantum dots have demonstrated very favorable properties for quantum computing, one remaining hurdle is the need to tune each of them into a good operating regime by adjusting the voltages applied to electrostatic gates. The automation of these tuning procedures is a necessary requirement for the operation of a quantum processor based on gate-defined quantum dots, which is yet to be fully addressed. We present an algorithm for the automated fine-tuning of quantum dots, and demonstrate its performance on a semiconductor singlet-triplet qubit in GaAs. The algorithm employs a Kalman filter based on Bayesian statistics to estimate the gradients of the target parameters as function of gate voltages, thus learning the system response. The algorithm's design is focused on the reduction of the number of required measurements. We experimentally demonstrate the ability to change the operation regime of the qubit within 3 to 5 iterations, corresponding to 10 to 15 minutes of lab-time

The Architecture of Talin1 Reveals an Autoinhibition Mechanism

Focal adhesions (FAs) are protein machineries essential for cell adhesion, migration, and differentiation. Talin is an integrin-activating and tension-sensing FA component directly connecting integrins in the plasma membrane with the actomyosin cytoskeleton. To understand how talin function is regulated, we determined a cryoelectron microscopy (cryo-EM) structure of full-length talin1 revealing a two-way mode of autoinhibition. The actin-binding rod domains fold into a 15-nm globular arrangement that is interlocked by the integrin-binding FERM head. In turn d domains R9 and R12 shield access of the FERM domain to integrin and the phospholipid PIP2 at the membrane. This mechanism likely ensures synchronous inhibition of integrin, membrane, and cytoskeleton binding. We also demonstrate that compacted talin1 reversibly unfolds to an similar to 60-nm string-like conformation, revealing interaction sites for vinculin and actin. Our data explain how fast switching between active and inactive conformations of talin could regulate FA turnover, a process critical for cell adhesion and signaling

De gelukkige huurder:het bewaken van de kwaliteit en het tevreden stellen van de huurder binnen gemeente Helmond

Het doel van dit rapport: Een meetinstrument ontwikkelen met betrekking tot klanttevredenheid van de huurders, waarin de kwaliteit van de dienstverlening en het vastgoed wordt gemeten. Aan de hand van dit rapport wordt er antwoord gegeven op de vraag: Aan welke onderdelen van de gemeentelijke dienstverlening hechten de huurders van maatschappelijk vastgoed waarde en wat voor belang hebben zij bij de kwaliteit van het vastgoed? In de oriëntatie wordt het onderzoeksonderwerp afgebakend. Vervolgens wordt het probleem beschreven en deelvragen geformuleerd. Aan de hand van de deelvragen en de oriëntatie kunnen er aan aantal verwachtingen worden geformuleerd. De volgende stap in het onderzoek is het vaststellen van de onderzoeksmethode. De onderzoeksmethode wordt in hoofdstuk 5 uitgewerkt waar antwoord wordt gegeven op de deelvragen die in hoofdstuk 3 aan bod komen. Als laatste wordt de uitwerking van de deelvragen gebruikt voor het opstellen en onderbouwen van de enquête waarin de tevredenheid van de huurders van het maatschappelijk vastgoed zal worden gemeten. Studentonderzoek in het kader van het thema Leefomgevin

Stable isotopes infer the diet and habitat of the enigmatic pygmy right whale (Caperea marginata) off southern Australia

In the Southern Hemisphere, baleen whales generally undertake migrations between productive feeding grounds at high latitudes and breeding grounds at lower latitudes. Pygmy right whales (Caperea marginata) (PRW) are the smallest and most enigmatic baleen whale, that likely forgo long-distance migrations, and instead inhabit temperate and subantarctic waters year-round. Previous research has relied on limited data from sighting and stranding records to infer the habitat use and diet of PRWs, however the absence of long-term and consistent data has left uncertainty surrounding these parameters. We utilized bulk stable isotopes of carbon (δ13C) and nitrogen (δ15N) in baleen from Australian PRWs (n = 14) to infer their diet and habitat use. Stable isotope values from 1980–2019 were then matched to remote sensed data from known upwelling regions (where they likely feed) to examine if their dietary patterns are related to changes in food web dynamics. We found that PRWs remained in mid-latitude waters year-round and showed no evidence of feeding in Antarctic waters. Rather, their isotopic record suggests they remain between coastal waters off southern Australia and the Subtropical Convergence, feeding on krill and copepods. Additionally, there was a weak positive relationship between PRW nitrogen stable isotope values and sea surface temperature (SST) from the eastern Great Australian Bight (GAB) and Bonney Upwelling. This suggests seasonal changes in their diet is possibly correlated to oceanographic changes which drive food-web dynamics in these regions. Unlike larger species of baleen whales that migrate further to highly productive waters in the Southern Ocean to meet their energetic demands, the small PRW, who only reach 6.5m, may sustain both feeding and breeding requirements at mid-latitudes. This is the first study to analyze long-term dietary and movement patterns of the PRW, providing an important contribution to our understanding of the species

Вредные производственные факторы производства цемента

В статье проанализировано влияние вредных производственных факторов на работников цементных заводов, приведены статистические данные, охарактеризованы средства защиты от цементной пыли.The article analyzes the impact of harmful production factors on employees of cement plants, provides statistical data, and describes the means of protection from cement dust

Adhesions Assemble!—Autoinhibition as a Major Regulatory Mechanism of Integrin-Mediated Adhesion

The advent of cell-cell and cell-extracellular adhesion enabled cells to interact in a coherent manner, forming larger structures and giving rise to the development of tissues, organs and complex multicellular life forms. The development of such organisms required tight regulation of dynamic adhesive structures by signaling pathways that coordinate cell attachment. Integrin-mediated adhesion to the extracellular matrix provides cells with support, survival signals and context-dependent cues that enable cells to run different cellular programs. One mysterious aspect of the process is how hundreds of proteins assemble seemingly spontaneously onto the activated integrin. An emerging concept is that adhesion assembly is regulated by autoinhibition of key proteins, a highly dynamic event that is modulated by a variety of signaling events. By enabling precise control of the activation state of proteins, autoinhibition enables localization of inactive proteins and the formation of pre-complexes. In response to the correct signals, these proteins become active and interact with other proteins, ultimately leading to development of cell-matrix junctions. Autoinhibition of key components of such adhesion complexes—including core components integrin, talin, vinculin, and FAK and important peripheral regulators such as RIAM, Src, and DLC1—leads to a view that the majority of proteins involved in complex assembly might be regulated by intramolecular interactions. Autoinhibition is relieved via multiple different signals including post-translation modification and proteolysis. More recently, mechanical forces have been shown to stabilize and increase the lifetimes of active conformations, identifying autoinhibition as a means of encoding mechanosensitivity. The complexity and scope for nuanced adhesion dynamics facilitated via autoinhibition provides numerous points of regulation. In this review, we discuss what is known about this mode of regulation and how it leads to rapid and tightly controlled assembly and disassembly of cell-matrix adhesion