Proefschrift--Faculteit der Sociale Wetenschappen--Leiden--Rijksuniversiteit, 1998. / Bibliogr. p. 253-278. Notes bibliogr.

Th. 3e cycle--Chim. org.--Lille 1, 1979. N°: 748.

The synthesis, reactivity, and spectroscopic properties of a series of triangular phosphido-bridged rhodium, iridium, palladium and platinum clusters are described. Throughout the project, X-ray diffraction and 31P{1H} NMR spectroscopy are the main techniques for characterizing compounds. In the first part of this report, the lability of μ-X and terminal phosphines in [M3(μ-X)(μ-PPh2)2(PPh3)3)[BF4](M= Pd, X= Cl; M=Pt, X= H) is utilized to prepare a number of compounds where the integrity of the triangular framework is maintained. The molecular structures of three representative examples: [Pd3(μ-SCH2Ph)(μ-PPh2)2(PEt3)3][BF4] [Pt3(μ-Cl)(μ-PPh2)2(PR3)3][BF4) (R= Ph, Et) were determined and are described. Reaction of these palladium and platinum trinuclear clusters with chelating ligands, R’2PYPR”2 (Y= O, CH2), results in unusual cluster fragmentation to give novel dinuclear monocations, [M2(μ-PP2)(μ-R’2PYPR”2) (PR3)2)+ (M= Pd, Pt) in which a metal-metal bond is supported by both dppm and phosphido bridges. These dimers are very inert failing to react with a number of reagents including C4H6, HCCCO2Me, CH2N2, CO, CH3I (when M= Pd), H2, HBF4 and CH2I2. The cluster, [Pt3(μ-H)(μ-PPh2)2(PPh3)3] [BF4], also reacts with ButNC to afford the dinuclear species (Pt2(μ-PPh2)2(ButNC)(PPh3)3]+. The crystal structures of fragmentation products [Pd2(μ-PPh2)( μ-Pri2PCH2PPh2)(PPh3)2] [BF4], (Pt2(μ-PPh2)( μ-Me2PCH2PMe2)(PPh3)2]2 [C2O4] and (Pt2(μ-PPh2)(ButNC)(PPh3)3]2(C2O4) are reported and discussed. In the last part, the synthesis of a novel trinuclear iridium cluster, [Ir3(μ-PPh2)3(CO)5], is described, and the reactions of this cluster and its previously reported rhodium analogue, [Rh3(μ-PPh2)3(PPh3)2(CO)3], with dppm afford not fragmentation, but substitution products. The complex (Ir3(μ-PPh2)3(CO)5] also reacts with ButNC to yield [Ir3(μ-PPh2)3(CO)5(ButNC)2]. The crystal structures of the compounds, [M3(μ-PPh2)3(μ-dppm)(CO)3] (M= Rh, Ir) and (Ir3(μ-PPh2)3(CO)5(ButNC)2], are also reported. / Graduate

No description available.

With psychiatric disabilities representing a large number of transition-age youth in the US and low employment rates for individuals with disabilities in general, it is necessary to identify the patterns of service variables that are more likely to lead to a competitive employment outcome for this population. This study was an investigation of the vocational rehabilitation case service variables provided through the federal-state vocational rehabilitation system to transition-age consumers with psychiatric disabilities. The identified variables were then studied to determine relationships that exist as they pertain to employment outcomes. The population of vocational rehabilitation consumers was accessed using the Rehabilitation Services Administration 911 database for fiscal year 2007. The database was analyzed using a series of cluster analyses to determine patterns of services associated with competitively employed or unemployment outcomes for this population. A total of 5744 cases were analyzed in this study. The results indicated that there were three distinct clusters of vocational rehabilitation services delivered to this population: Basic services, Job Focused, and College Plus. The results also showed that employment status at application, medical insurance at closure, Job Focused Cluster, and race - African American were significant predictors of rehabilitation outcome. Significant predictors of yearly earnings at closure were employment status at application, medical insurance at closure, Basic Services Cluster, and Job Focused Cluster. The Hispanic race was not found to be a significant predictor in this study. Implications, suggestions for future research, and limitations of the study are discussed.

DISSERTATION ABSTRACT Li Jin Doctor of Philosophy Department of Human Physiology March 2018 Title: Kinematic and Kinetic Analysis of Walking and Running across Speeds and Transitions between Locomotion States Walking and running are general locomotion activities for human beings. Basic gait patterns and whole body center of mass (COM) dynamic patterns are distinctly different between them. Lower extremity joint mechanics patterns could reflect musculoskeletal coordination characteristics. Change of locomotion tasks and speeds can affect lower extremity joint kinematic and kinetic characteristics, and progression of age may also affect these characteristics. Little is known about change of locomotion tasks and speeds effects on lower extremity joint level kinetic characteristics, and whether there is a connection between COM system and lower extremity system. To address this, twenty healthy subjects were recruited to participate in a series of treadmill tests, including walking (0.8 – 2.0 m/s, with 0.2 m/s intervals), running (1.8 – 3.8 m/s, with 0.4 m/s intervals) and gait mode transition from walking to running, and from running to walking (between 1.8 – 2.4 m/s, 0.1 m/s2). Three-dimensional kinematic and kinetic data were collected in all locomotion tests and used to calculate and analyze outcome variables for lower extremity joints and the COM system across different conditions. Results indicate that change of locomotion speeds significantly affect joint level kinetic characteristics within both walking and running locomotion states. Different locomotion task demands (walking vs. running) require fundamental alteration of lower extremity joint level kinetic patterns, even at the same locomotion speed. Progression of age also affects lower extremity joint level kinematic and kinetic patterns in walking and running across speeds. Additionally, stance phase an energy generation and transfer phenomenon occurred between the distal and proximal joints of the lower extremity in both walk-to-run and run-to-walk transitions. Lastly, a connection exists between whole body COM oscillation patterns and lower extremity joint level kinetic characteristics in running. These findings serve to further clarify the mechanisms involved in change of locomotion tasks and speeds effects on lower extremity joint kinetic patterns, and further establish a connection between the COM system and the lower extremity system. These findings may be beneficial for future foot-ankle assistive device development, potential optimization of gait efficiency and performance enhancement. This dissertation includes previously published and unpublished coauthored material.

Past theoretical research has explored whether bribes paid by firms to government officials are greater under a decentralized bureaucracy where the firm faces numerous government officials or under a monopolistic one. Presumably, bribes are bid down in the former as officials compete for bribes. However, a tragedy of the commons could occur where decentralized officials "overgraze" and charge higher bribes than a single bureaucrat would. Using the BEEPS I, a firm level survey covering 24 transition countries, the chapter 1 examines whether reported bribe payments by firms are higher when firms face numerous officials or only a single one. We find that bribe payments are higher under a more decentralized bureaucratic structure. In chapter 2 we investigate the link between private market competition and bribery. Greater competition could lower profits thereby limiting the amount corruption since rents are lower but greater competition could also provide more incentives for firms to pay bribes to obtain advantages over their rivals. We consider bribes to obtain government contracts. Using the BEEPS III dataset on 27 transition countries and the Censored Quantile Regression methodology we empirically found that as the number of competitors increases the amount bribes paid tend to increase as well. We also found that this relationship follows an inverted U. The marginal effect increases with the amount of bribes paid up to a maximum, then decreases, but remains positive. We believe that this relationship is driven by more competitors raising demand for these contracts. In chapter 3 we investigate the association between corruption and two types of investment. Past research focuses only on the total level of investment. Using the same dataset as used in chapter 2, we obtain mixed results. Using a tobit model, we find evidence that corruption "greases the wheels" of physical investment but has no significant effect on the level of R&D investment. However, results from a probit model suggest that corruption does negatively impact whether or not the firm undertakes R&D. These findings indicate corruption can affect not only the level but also the decision of whether to invest. They also show that these effects might differ across the type of investment so that the "grease wheels" and "sand wheels" perspectives are not incompatible as most the studies using the aggregate level of investment tend to imply.

No description available.

A systematic review of the literature that explored the processes and perceived effectiveness of qualitative methods used to elicit the views of young people with autism spectrum disorders (ASD) about their educational experiences was conducted. Studies that were identified and screened using a trialled evaluation checklist and synthesised using the PRISMA guidelines identified data collection methods that were perceived to be useful. Limitations such as the over-representation of participants who were able to engage in verbal discussion and the lack of detailed description and evaluation of data collection methods were also identified. A multiple case study research was then conducted to explore two special schools' processes of eliciting the views of secondary school-aged pupils with ASD about their transition to adulthood and its perceived effectiveness. Qualitative data from semi-structured interviews with the school's staff and an observation of a transition meeting were gathered and thematically analysed individually, then compared and contrasted within school level. The findings revealed that both schools' processes of eliciting young people with ASD's views about transition to adulthood is a long process which involves three phases and is underpinned by a person-centred ethos. Perceived strengths and limitations of the process were also identified. Dissemination of the study's findings will include presentations and consultations with key stakeholders such as mainstream and specialist secondary schools and local authority post-16 steering group to explore the utility of the findings in different contexts. Collaboration with other educational psychologists (EPs) will also be conducted to explore this study's implications in the way they support schools in eliciting the views of young people with ASD.

The scope of the palladium catalysed allylic substitution reaction is reviewed with particular reference to stereocontrol. The use of enantiopure oxazolines and acetals in asymmetric synthesis is briefly outlined. The work presented is concerned with the design and construction of enantiopure ligands which are able to impart very high levels of enantioselectivity in the aforementioned palladium-catalysed allylic substitution reaction. The ligands exploit the stereochemistry-controlling properties of the oxazoline moiety, whilst incorporating a secondary donor atom. The ligands rely upon an electronic disparity between these two atoms to direct nucleophilic addition.