In the "Internet of Things" (IoT), the things will be able to sense, communicate, and interact. They will also exchange data, information and knowledge, and locate themselves and other things that surround them. In order to be able to interact, the things need to recognize that they are in proximity of other things. It is anticipated that the most widespread components of the IoT will be passive radio frequency identification (RFID) tags because they are inexpensive and provide automatic identification. However, passive RFID tags are not capable of performing complex operations, such as proximity detection and localization, which will be required in future networks. In this thesis, we describe existing problems with current RFID systems and survey potential solutions for localization and proximity detection. Then we present a new RFID device called "Sense-a-Tag" (ST) that can passively detect and decode backscattered signals from tags in its proximity. There have already been an attempt to use this device for tracking. However, detailed analysis of the performance of the ST especially for proximity detection has not been performed yet. We show that when STs are added to a standard RFID system, the problems of proximity detection and localization with RFID tags can readily be solved. Then we applied ST-based system for identifying people and object interactions. The potential uses of ST as an augmented device for IoT applications are discussed in this thesis. Advantages and limitations of an ST based RFID system have been investigated in details for each application. Results obtained from real experiments illustrate that an ST-based RFID system is feasible for proximity detection applications. In addition, a special software is developed in C\# to process the data and run a localization algorithm based on proximity detection information. The same software has been used for tracking people's activity. Different scenarios have been considered in the experiments. We tried to consider majority of factors that might affect the accuracy in the experiments including: angle and distance between the reader/ST and tags, timing in sending queries, presence of human body, etc. The simulations based on real experiments and results illustrates that an ST-based RFID system can be a realistic solution for proximity detection and localization for Location Positioning systems (LPS) and activity monitoring in future IoT.

Harnessing the immune system is a powerful tool in chemical biology and is the focus of cancer immunotherapy. Often, this is accomplished through monoclonal antibodies which recognize and recruit immune effector cells to an over-expressed cancer antigen presented at the cancer cell surface. More recently, there has been great interest in developing small molecule therapeutics which replicate this, but with lower developmental costs, greater modularity, and improved tumor penetration. One such class of therapeutics are bifunctional molecules known as antibody recruiting molecules, which form molecular bridges between two targets, i.e., a cancer receptor and antibody. Limitations in ternary complex formation between bifunctional molecules and their two binding targets has presented the need for increasing residence time at key junctions. Demonstrated here is the development of a covalent proximity-induction approach which leverages molecular recognition to drive an electrophilic warhead near a nucleophile within a target antibody binding site. Subsequent irreversible labeling reprograms these antibodies with tumor binding handles in situ for enhanced tumor opsonization and immune clearance mechanisms. This was accomplished by equipping a viral peptide epitope with a sulfur (VI) fluoride exchange electrophile to irreversibly label anti-herpes simplex virus (HSV) antibodies. Using the aryl sulfonyl fluoride warhead, we demonstrate fast and selective labeling for both model monoclonal antibodies, as well as natural polyclonal anti-HSV antibodies. Covalently reprogrammed antibodies elicited superior potency at both lower concentrations and with cell lines having lower antigen presentation. This proof of concept has broad applicability in developing covalent bifunctional molecules for bridging one or more protein:protein interactions. / Dissertation / Master of Science (MSc)

This thesis aims to deepen the relationship between the different forms of proximity that emerge between economic actors and the consequent influence on their innovative capacity. Over the years, this topic has generated a great deal of attention in conference proceedings and scientific publications. The first step to deepen the understanding of this amount of knowledge was to identify a suitable methodology. In so do- ing, the recent advances of the Machine Learning community – particularly Natural Language Processing academics - have offered interesting insights. In particular, "Topic Modeling" was identified as a suitable methodology to bring out latent semantic structures. Therefore, the first chapter tries to study how this methodology has been implemented in the social sciences and, in particular, in management. The contribution offered is a rationalization of the achievable goals and their relationship with evaluation practices. Once clarified how to use this algorithm, the second chapter studied the relationship between proximity and innovation. Using an unsupervised machine learning technique, the research attempts to identify thematic management cores in a multifocal literature such as proximity. Together with a qualitative analysis, the study attempts to bring out the theoretical and empirical contributions offered to the management community. Once the theoretical and empirical expectations have been clarified, the third chapter introduces a strategic theme, namely the business model. This section proposes a mediating effect of the business model concerning the central relationship between proximity and innovation. After a theoretical introduction, the conceptual model is studied with an exploratory approach. Without any presumption of generalizability and completeness, a novel analytical key is offered to open further debate in the community of proximity.

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The COVID-19 pandemic and subsequent shutdown and regulations have drastically altered the world of competitive sports. The global shutdown beginning in March 2020 put a significant strain on athlete's ability to train, as many fitness centers were closed to prevent disease transmission. When it was deemed that athletic competition was safe to resume, there were still strict regulations in place to support public health efforts. This retrospective study primarily aims to evaluate the effectiveness of COVID-19 safety regulations in competitive sports. Specifically, the successfulness to correctly implement social distancing guidelines is of high interest. A secondary aim of this study is to assess changes in workload during preseason training before COVID-19, during the time of heavily enforced COVID-19 regulations, and following strict COVID-19 restrictions, as workload can be a predictor of athletic injury. Participants in this study included Virginia Tech Women's Soccer athletes and data were analyzed from the first 9 preseason training sessions during the 2019, 2020, 2021 and 2022 seasons. Data were generated from participants wearing the STATSports Apex device during training. A custom MATLAB spatiotemporal program developed by the Williams Research Group was utilized to determine player proximity. Total distance (m) and high metabolic load (HMLD) (au), and high-speed distance (HSD) (m) metrics were analyzed to understand changes in participant workload. It was found that overall the Virginia Tech Women's Soccer Team's implementation of the guidelines was effective, as there were no invasion violations during the 2020 preseason sample. / Master of Science / The COVID-19 pandemic has forever changed the world as we know it. Competitive sports are no exception. The worldwide shutdown as a result of COVID-19 made it difficult for athletes to train while in isolation, as most facilities were closed to prevent disease transmission. When sports were able to continue again, there were still barriers preventing normal practices and competition. Athletes were asked to make every effort to maintain social distancing, even during training sessions. The main purpose of this study is to evaluate how well NCAA Division 1 Women's Collegiate Soccer players maintained social distancing during preseason practices. A secondary goal of this study is to uncover changes in workload from before COVID-19 (2019), during strict COVID-19 regulations (2020), and when COVID-19 restrictions had been less enforced (2021 and 2022). The reasoning for this is that how much work an athlete does can be indicative of risk for injury. If an athlete does significantly more work than usual, there is a higher risk of injury. This study will use global positioning systems (GPS) and measures that reflect workload collected from Virginia Tech Women's Soccer players. It was found that the players remained farther apart during the 2020 season due to the emphasis on social distancing, and that the workload will show a gradual increase to prevent injury. Overall, the study found that the COVID-19 regulations were effectively implemented among the Virginia Tech Women's Soccer Team in the 2020 preseason when restrictions were the highest.

Thesis advisor: Eranthie Weerapana / Reactive oxygen species (ROS) modulate protein function through cysteine oxidation. Identifying protein targets of ROS can provide insight into uncharacterized ROS-regulated pathways especially within ROS generating organelles such as the mitochondria. There are several known examples of mitochondrial cysteine targets that alter protein and pathway activity resulting in pathological effects. Several chemoproteomic workflows, including ABPP and OxICAT, can be used to identify sites of cysteine oxidation. However, determining ROS targets localized within subcellular regions and ROS hotspots remains challenging with existing workflows. Here, we present combined cysteine- monitoring chemoproteomic platforms (isoTOP-ABPP and OxICAT) with mitochondrial enrichment (organelle isolation and proximity labeling) to monitor cysteine oxidation events within the mitochondria. First, we profile redox- sensitive cysteines under exogenous and endogenous peroxide in isolated mitochondria using isoTOP-ABPP and OxICAT. Next, we introduce PL-OxICAT which combines enzymatic proximity labeling (PL) (TurboID/APEX) and OxICAT to monitor localized cysteine oxidation events within subcellular compartments such as the mitochondrial matrix and intermembrane space as well as ROS hotspots. Together, these platforms further hone our ability to monitor cysteine oxidation events within specific subcellular locations and ROS hotspots and provide a deeper understanding of the protein targets of endogenous and exogenous ROS. / Thesis (PhD) — Boston College, 2022. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Chemistry.

The intergalactic medium is kept highly photoionised by the intergalactic UV background radiation field generated by the overall population of quasars and galaxies. In the vicinity of sources of UV photons, such as luminous high-redshift quasars, the UV radiation field is enhanced due to the local source contribution. The higher degree of ionisation is visible as a reduced line density or generally as a decreased level of absorption in the Lyman alpha forest of neutral hydrogen. This so-called proximity effect has been detected with high statistical significance towards luminous quasars. If quasars radiate rather isotropically, background quasar sightlines located near foreground quasars should show a region of decreased Lyman alpha absorption close to the foreground quasar. Despite considerable effort, such a transverse proximity effect has only been detected in a few cases. So far, studies of the transverse proximity effect were mostly limited by the small number of suitable projected pairs or groups of high-redshift quasars. With the aim to substantially increase the number of quasar groups in the vicinity of bright quasars we conduct a targeted survey for faint quasars around 18 well-studied quasars at employing slitless spectroscopy. Among the reduced and calibrated slitless spectra of 29000 objects on a total area of 4.39 square degrees we discover in total 169 previously unknown quasar candidates based on their prominent emission lines. 81 potential z>1.7 quasars are selected for confirmation by slit spectroscopy at the Very Large Telescope (VLT). We are able to confirm 80 of these. 64 of the newly discovered quasars reside at z>1.7. The high success rate of the follow-up observations implies that the majority of the remaining candidates are quasars as well. In 16 of these groups we search for a transverse proximity effect as a systematic underdensity in the HI Lyman alpha absorption. We employ a novel technique to characterise the random absorption fluctuations in the forest in order to estimate the significance of the transverse proximity effect. Neither low-resolution spectra nor high-resolution spectra of background quasars of our groups present evidence for a transverse proximity effect. However, via Monte Carlo simulations the effect should be detectable only at the 1-2sigma level near three of the foreground quasars. Thus, we cannot distinguish between the presence or absence of a weak signature of the transverse proximity effect. The systematic effects of quasar variability, quasar anisotopy and intrinsic overdensities near quasars likely explain the apparent lack of the transverse proximity effect. Even in absence of the systematic effects, we show that a statistically significant detection of the transverse proximity effect requires at least 5 medium-resolution quasar spectra of background quasars near foreground quasars whose UV flux exceeds the UV background by a factor 3. Therefore, statistical studies of the transverse proximity effect require large numbers of suitable pairs. Two sightlines towards the central quasars of our survey fields show intergalactic HeII Lyman alpha absorption. A comparison of the HeII absorption to the corresponding HI absorption yields an estimate of the spectral shape of the intergalactic UV radiation field, typically parameterised by the HeII/HI column density ratio eta. We analyse the fluctuating UV spectral shape on both lines of sight and correlate it with seven foreground quasars. On the line of sight towards Q0302-003 we find a harder radiation field near 4 foreground quasars. In the direct vicinity of the quasars eta is consistent with values of 25-100, whereas at large distances from the quasars eta>200 is required. The second line of sight towards HE2347-4342 probes lower redshifts where eta is directly measurable in the resolved HeII forest. Again we find that the radiation field near the 3 foreground quasars is significantly harder than in general. While eta still shows large fluctuations near the quasars, probably due to radiative transfer, the radiation field is on average harder near the quasars than far away from them. We interpret these discoveries as the first detections of the transverse proximity effect as a local hardness fluctuation in the UV spectral shape. No significant HI proximity effect is predicted for the 7 foreground quasars. In fact, the HI absorption near the quasars is close to or slightly above the average, suggesting that the weak signature of the transverse proximity effect is masked by intrinsic overdensities. However, we show that the UV spectral shape traces the transverse proximity effect even in overdense regions or at large distances. Therefore, the spectral hardness is a sensitive physical measure of the transverse proximity effect that is able to break the density degeneracy affecting the traditional searches. / Das intergalaktische Medium wird durch das intergalaktische UV-Hintergrundsstrahlungsfeld in einem hochgradig photoionisierten Zustand gehalten. Der UV-Hintergrund stammt von der gesamten Population von Quasaren und Galaxien. In der Nähe von leuchtkräftigen Quasaren, ist das UV-Strahlungsfeld lokal erhöht durch den Anteil der Quelle. Der höhere Ionisationsgrad ist beobachtbar als eine reduzierte Liniendichte oder allgemein als ein vermindertes Maß an Absorption im Lyman-alpha Wald des neutralen Wasserstoffs. Dieser sogenannte Proximity-Effekt ist bei leuchtkräftigen Quasaren mit hoher statistischer Signifikanz nachgewiesen worden. Falls Quasare fast isotrop strahlen, dann sollten Sichtlinien zu Hintergrundquasaren in der Nähe von Vordergrundquasaren eine Region mit verminderter Absorption zeigen. Trotz beträchtlichen Aufwands wurde solch ein transversaler Proximity-Effekt nur in wenigen Fällen entdeckt. Bisher waren Studien des transversalen Proximity-Effekts meist begrenzt durch die kleine Anzahl von geeigneten projizierten Paaren oder Gruppen von hochrotverschobenen Quasaren. Mit dem Ziel die Zahl der Quasargruppen in der Nähe von hellen Quasaren beträchtlich zu erhöhen, führen wir eine gezielte Suche nach schwachen Quasaren um 18 oft studierte Quasare durch. Unter den reduzierten und kalibrierten spaltlosen Spektren von 29000 Objekten auf einer Gesamtfläche von 4.39 Quadratgrad entdecken wir insgesamt 169 vorher unbekannte Quasarkandidaten anhand ihrer Emissionslinien. 81 potentielle z>1.7 Quasare werden ausgesucht zur Bestätigung mittels Spaltspektroskopie am Very Large Telescope (VLT). Wir können 80 von diesen als Quasare bestätigen. 64 der neu entdeckten Quasare liegen bei z>1.7. Die hohe Erfolgsrate der Nachfolgebeobachtungen deutet an, dass die Mehrzahl der verbleibenden Kandidaten ebenfalls Quasare sind. In 16 dieser Gruppen suchen wir nach dem transversalen Proximity-Effekt als eine systematische Unterdichte in der HI Lyman-alpha-Absorption. Wir nutzen eine neuartige Methode die zufälligen Absorptionsfluktuationen zu charakterisieren, um die Signifikanz des transversalen Proximity-Effekts abschätzen zu können. Weder schwach aufgelöste noch hoch aufgelöste Spektren von Hintergrundquasaren unserer Gruppen zeigen Anzeichen für einen transversalen Proximity-Effekt. Aufgrund von Monte Carlo Simulationen sollte der Effekt jedoch nur schwach in der Nähe von 3 Vordergrundquasaren detektierbar sein. Deshalb können wir nicht zwischen An- oder Abwesenheit des Effekts unterscheiden. Selbst in Abwesenheit von systematischen Effekten zeigen wir, dass eine statistisch signifikante Detektion des transversalen Proximity-Effekts mindestens 5 Hintergrundquasarspektren bei mittlerer Auflösung nahe Vordergrundquasaren erfordert, deren UV-Fluss den UV-Hintergrund um einen Faktor 3 übersteigt. Deshalb erfordern statistische Studien des transversalen Proximity-Effekts große Zahlen von geeigneten Quasaren. Zwei Sichtlinien zeigen HeII-Absorption. Ein Vergleich der HeII-Absorption mit der entsprechenden HI-Absorption liefert eine Abschätzung der Spektralform des UV-Strahlungsfelds, das typischerweise durch das HeII/HI Säulendichteverhältnis eta parameterisiert wird. Wir analysieren die fluktuierende spektrale Form des UV-Strahlungsfelds auf beiden Sichtlinien und korrelieren sie mit 7 Vordergrundquasaren. Auf der Sichtlinie zu Q0302-003 finden wir ein härteres Strahlungsfeld nahe 4 Vordergrundquasaren. In der direkten Umgebung der Quasare ist eta konsistent mit Werten von 25-100, wogegen bei großen Entfernungen zu den Quasaren eta>200 erforderlich ist. Die zweite Sichtlinie zu HE2347-4342 sondiert kleinere Rotverschiebungen. Wieder finden wir, dass das Strahlungsfeld nahe der 3 Vordergrundquasaren signifikant härter ist als im allgemeinen. Während eta trotzdem große Fluktuationen nahe den Quasaren aufweist, die wahrscheinlich von Strahlungstransport herrühren, ist das Strahlungsfeld in der Nähe der Quasare im Mittel härter als in großer Entfernung. Wir interpretieren diese Entdeckungen als die ersten Detektionen des transversalen Proximity-Effekts als eine lokale Fluktuation im spektralen Härtegrad. Kein signifikanter HI Proximity-Effekt ist für die 7 Vordergrundquasare vorhergesagt. Tatsächlich ist die HI-Absorption nahe den Quasaren nahe am oder etwas über dem Mittelwert, was darauf hindeutet, dass die schwache Signatur des transversalen Proximity-Effekts maskiert wird durch intrinsische Überdichten. Jedoch zeigen wir, dass der Härtegrad den transversalen Proximity-Effekt selbst in überdichten Regionen oder auf großen Distanzen sichtbar werden läßt. Deshalb ist der spektrale Härtegrad ein empfindliches physikalisches Maß für den transversalen Proximity-Effekt, der in der Lage ist, die Dichteentartung zu brechen, die die traditionelle Suche behindert.

In New Zealand, a formal tree improvement and breeding programme for Pinus radiata (D.Don) commenced in 1952. A countrywide series of progeny trials was progressively established on over seventy sites, and is managed by the Radiata Pine Breeding Company (RPBC). Diameter at breast height data from the series were used to investigate genotype x environment interaction with a view to establishing the need for partitioning breeding and deployment efforts for P. radiata. Nearly 300,000 measurements made this study one of the largest for genotype x environment interaction ever done. Bivariate analyses were conducted between all pairs of sites to determine genetic correlations between sites. Genetic correlations were used to construct a proximity matrix by subtracting each correlation from unity. The process of constructing the matrix highlighted issues of low connectivity between sites; whereby meaningful correlations between sites were established with just 5 % of the pairs. However, nearly two-thirds of these genetic correlations were between -1.0 and 0.6, indicating the presence of strong genotype x environment interactions. A technique known as multiple regression on resemblance matrices was carried out by regressing a number of environmental correlation matrices on the diameter at breast height correlation matrix. Genotype x environment interactions were found to be driven by extreme maximum temperatures (t-statistic of 2.03 against critical t-value of 1.96 at 95 % confidence level). When tested on its own, altitude was significant with genetic correlations between sites at the 90 % confidence level (t-statistic of 1.92 against critical t-value of 1.645). In addition, a method from Graph Theory using proximity thresholds was utilised as a form of clustering. However, this study highlighted the existence of high internal cohesion within trial series, and high external isolation between trial series. That is, grouping of sites (in terms of diameter) was observed to be a reflection of the series of trials for which each site was established. This characteristic is particularly unhelpful for partitioning sites into regions of similar propensity to genotype x environment interaction, as the genotype x environment effect is effectively over-ridden by the genotype effect. Better cohesion between past, present and future trial series, and more accurate bioclimatic data should allow more useful groupings of sites to be extracted from the data. Given this, however, it is clear that there are a large number of interactive families contained in the RPBC dataset. It is concluded that partitioning of New Zealand’s P. radiata breeding programme cannot be ruled out as an advantageous option.

The U.S. construction industry continues to rank as one of the most dangerous work environments when compared to other industrial sectors. Construction companies are required to record and report lagging safety leading indicators including fatalities, injuries, and illnesses. Safety leading indicators provide an opportunity to identify construction site hazards and hazardous worker behavior before a fatality, injury, or illness occurs. Further improvements are also necessary for construction safety through the use of technology. The application of advanced or emerging technologies can have a significant role in enhancing construction worker safety performance. This research seeks to report and analyze safety leading indicators, specifically near misses. Furthermore, technologies capable of providing alerts in real-time to construction equipment operators and ground workers during hazardous proximity situations are reviewed. A testing method for proximity detection and alert devices for the construction environment is presented. Operator visibility, including impacts of design components, is also measured and analyzed. One major contribution of this research is the creation of a near miss reporting program ready for implementation for construction companies. Other research contributions include understanding of impacts of design on operator visibility, scientific evaluation data of proximity sensing technology, and a test method for proximity detection and alert system deployed in the construction environment. Research findings can be disseminated for improved construction worker safety education and training.