63 research outputs found
Seeking tenure security: an analysis of the Communal Land Tenure Bill and its purported promise to give effect to section 25(6) of the Constitution.
Masters Degree. University of KwaZulu-Natal, Durban.Since the demise of apartheid, land reform has been one of the greatest challenges facing the
democratic dispensation. Section 25(6) of the Constitution provides that “a person or
community whose tenure of land is legally insecure as a result of past racially discriminatory
laws is entitled, to the extent provided by an Act of Parliament, either to tenure which is legally
secure or to comparable redress.” There is currently no comprehensive legislation which gives
effect to this right, despite various laws providing for some level of protection for security of
tenure to a certain extent, such as the Interim Protection of Informal Land Rights Act 62 of
1997.
One of the reasons for the delay in passing such legislation is the debate around the type of
entity which should be selected to administer land which is communally held, and the role of
traditional leaders. Traditional leaders were bolstered by the apartheid regime and have in some
instances abused their powers relating to communities residing on communal land. The
previous attempt to enact legislation to give effect to section 25(9) was challenged on the basis
that it allowed traditional councils to assume the role of land administration committees, which
could have resulted in the security of tenure of communities being diminished.
In 2017 the Department of Rural Development and Land Reform published the Communal
Land Tenure Bill in order to give effect to section 25(6) of the Constitution. The intended
purpose of the CLTB is to provide for the transfer of communal land to communities. This
dissertation will analyse the communal landholding entities proposed in the CLTB to
administer communal land, particularly communal property associations and traditional
councils, in an attempt to assess whether these entities would constitute a viable legal vehicle
to give effect to section 25(6) the Constitution and allow for democratic decision-making
relating to land use and allocation
PH-Dependent DNA Distortion and Repression of Gene Expression by Pectobacterium atrosepticum PecS
© 2016 American Chemical Society. Transcriptional activity is exquisitely sensitive to changes in promoter DNA topology. Transcription factors may therefore control gene activity by modulating the relative positioning of -10 and -35 promoter elements. The plant pathogen Pectobacterium atrosepticum, which causes soft rot in potatoes, must alter gene expression patterns to ensure growth in planta. In the related soft-rot enterobacterium Dickeya dadantii, PecS functions as a master regulator of virulence gene expression. Here, we report that P. atrosepticum PecS controls gene activity by altering promoter DNA topology in response to pH. While PecS binds the pecS promoter with high affinity regardless of pH, it induces significant DNA distortion only at neutral pH, the pH at which the pecS promoter is repressed in vivo. At pH ∼8, DNA distortions are attenuated, and PecS no longer represses the pecS promoter. A specific histidine (H142) located in a crevice between the dimerization- and DNA-binding regions is required for pH-dependent changes in DNA distortion and repression of gene activity, and mutation of this histidine renders the mutant protein incapable of repressing the pecS promoter. We propose that protonated PecS induces a DNA conformation at neutral pH in which -10 and -35 promoter elements are suboptimally positioned for RNA polymerase binding; on deprotonation of PecS, binding is no longer associated with significant changes in DNA conformation, allowing gene expression. We suggest that this mode of gene regulation leads to differential expression of the PecS regulon in response to alkalinization of the plant apoplast
The Stringent Response Induced by Phosphate Limitation Promotes Purine Salvage in Agrobacterium fabrum
© 2017 American Chemical Society. Agrobacterium fabrum induces tumor growth in susceptible plant species. The upregulation of virulence genes that occurs when the bacterium senses plant-derived compounds is enhanced by acidic pH and limiting inorganic phosphate. Nutrient starvation may also trigger the stringent response, and purine salvage is among the pathways expected to be favored under such conditions. We show here that phosphate limitation induces the stringent response, as evidenced by production of (p)ppGpp, and that the xdhCSML operon encoding the purine salvage enzyme xanthine dehydrogenase is upregulated ∼15-fold. The xdhCSML operon is under control of the TetR family transcription factor XdhR; direct binding of ppGpp to XdhR attenuates DNA binding, and the enhanced xdhCSML expression correlates with increased cellular levels of (p)ppGpp. Xanthine dehydrogenase may also divert purines away from salvage pathways to form urate, the ligand for the transcription factor PecS, which in the plant pathogen Dickeya dadantii is a key regulator of virulence gene expression. However, urate levels remain low under conditions that produce increased levels of xdhCSML expression, and neither acidic pH nor limiting phosphate results in induction of genes under control of PecS. Instead, expression of such genes is induced only by externally supplemented urate. Taken together, our data indicate that purine salvage is favored during the stringent response induced by phosphate starvation, suggesting that control of this pathway may constitute a novel approach to modulating virulence. Because bacterial purine catabolism appears to be unaffected, as evidenced by the absence of urate accumulation, we further propose that the PecS regulon is induced by only host-derived urate
Annotated Bibliography of Behavior Analytic Scholarship Outside of \u3ci\u3eAnalysis of Gambling Behavior\u3c/i\u3e: 2013-2015
Previous scholarly reviews have summarized behavior analytic gambling literature up to 2012 and have identified Analysis of Gambling Behavioras the primary journal for such scholarship. This article includes an annotated bibliography of behavioral literature centered on gambling and related issues published outside of Analysis of Gambling Behavior from 2013 to 2015
Exploration of Social Reinforcement for Gambling in Single Case Designs
Social reinforcement could be a variable that facilitates gambling behavior. Unfortunately, there are relatively few studies examining the impact that contingent social stimuli can have on betting behavior. Using simulated slot machine games and confederates, we investigated possible maintaining social contingencies for gambling with four recreational gamblers. Results indicated a small effect from a social positive reinforcement contingency for betting more credits than the previous trial. Four additional participants were recruited to replicate the effects of social positive reinforcement when structural aspects of the game were also changed, such as sound, win magnitude, and credit value. Lastly, one participant returned to the laboratory at a later time to examine the effects of different confederates providing social stimuli. This participant bet more in the presence of the confederate who had previously provided social positive reinforcement. Across the experiments, the social positive reinforcement contingency effect was replicated in five participants
Synthesis, Characterization of Dichlorofluorescein Silver Nanoparticles (DCF-SNPs) and Their Effect on Seed Germination of <em>Vigna radiata</em>
The main objective of this study was to investigate whether dichlorofluorescein (DCF) is adequate for the formulation of stable dichlorofluorescein-induced silver nanoparticles under the boiling method to analyze their effects on the seed germination of Mung seeds (Vigna radiata). Preliminary dichlorofluoresceine nanoparticles (DCF-SNPs) synthesis evidence by noticing the solution color transformed from a light green color to a dark brown color. The 2.5 ml of dichlorofluoresceine (DCF) solution was found sufficient for the formulation of dichlorofluoresceine induced silver nanoparticles at boiling conditions. Purified dichlorofluoresceine nanoparticles (DCF-SNPs) measure an average diameter of 293 nm where the majority of nanoparticles were around 159 nm in size with the surface load of-9.35 mV zeta potential value. The impact of dichlorofluorescein silver nanoparticles (DCF-SNPs) on the germination percentage of V. radiata has shown that, the 25% concentration of DCF-SNPs is excellent for the growth of Mung seeds (V. radiata). Overall, the dichlorofluorescein silver nanoparticles may be constructive for improving the percentage of seed germination at 25% of its concentration and may also be useful for fluorescent measurement using the confocal microscopy technique. Hence, dichlorofluorescein silver nanoparticles (DCF-SNPs) are proposed as an efficient detection system for nanoparticles in agrochemicals for plants
Histidine switch controlling pH-dependent protein folding and DNA binding in a transcription factor at the core of synthetic network devices
© 2016 The Royal Society of Chemistry. Therapeutic strategies have been reported that depend on synthetic network devices in which a urate-sensing transcriptional regulator detects pathological levels of urate and triggers production or release of urate oxidase. The transcription factor involved, HucR, is a member of the multiple antibiotic resistance (MarR) protein family. We show that protonation of stacked histidine residues at the pivot point of long helices that form the scaffold of the dimer interface leads to reversible formation of a molten globule state and significantly attenuated DNA binding at physiological temperatures. We also show that binding of urate to symmetrical sites in each protein lobe is communicated via the dimer interface. This is the first demonstration of regulation of a MarR family transcription factor by pH-dependent interconversion between a molten globule and a compact folded state. Our data further suggest that HucR may be utilized in synthetic devices that depend on detection of pH changes
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Transcription cofactor GRIP1 differentially affects myeloid cell-driven neuroinflammation and response to IFN-β therapy.
Macrophages (MФ) and microglia (MG) are critical in the pathogenesis of multiple sclerosis (MS) and its mouse model, experimental autoimmune encephalomyelitis (EAE). Glucocorticoids (GCs) and interferon β (IFN-β) are frontline treatments for MS, and disrupting each pathway in mice aggravates EAE. Glucocorticoid receptor-interacting protein 1 (GRIP1) facilitates both GR and type I IFN transcriptional actions; hence, we evaluated the role of GRIP1 in neuroinflammation. Surprisingly, myeloid cell-specific loss of GRIP1 dramatically reduced EAE severity, immune cell infiltration of the CNS, and MG activation and demyelination specifically during the neuroinflammatory phase of the disease, yet also blunted therapeutic properties of IFN-β. MФ/MG transcriptome analyses at the bulk and single-cell levels revealed that GRIP1 deletion attenuated nuclear receptor, inflammatory and, interestingly, type I IFN pathways and promoted the persistence of a homeostatic MG signature. Together, these results uncover the multifaceted function of type I IFN in MS/EAE pathogenesis and therapy, and an unexpectedly permissive role of myeloid cell GRIP1 in neuroinflammation
Effects of Vagus Nerve Stimulation on Sleep-related Breathing in Epilepsy Patients
Purpose: To describe the effects of vagus nerve stimulation (VNS) on sleep-related breathing in a sample of 16 epilepsy patients. Methods: Sixteen adults with medically refractory epilepsy (nine men, seven women, ages 21–58 years) underwent baseline polysomnograms (PSGs). Three months after VNS therapy was initiated, PSGs were repeated. In addition, patient 7 had a study with esophageal pressure monitoring, and patient 1 had a continuous positive airway pressure (CPAP) trial. Results: Baseline PSGs: One of 16 patients had an apnea–hypopnea index (AHI) >5 (6.8). Treatment PSGs: Five of 16 patients had treatment AHIs >5. Respiratory events were more frequent during periods with VNS activation (on-time) than without VNS activation (off-time; p = 0.016 ). Follow-up studies: Esophageal pressure monitoring in patient 7 showed crescendos in esophageal pressure during VNS activation, supporting an obstructive pattern. The CPAP trial of patient 1 showed that all respiratory events were associated with VNS stimulation at low CPAP levels. They were resolved at higher CPAP levels. Conclusions: Treatment with VNS affects respiration during sleep and should be used with care, particularly in patients with preexisting obstructive sleep apnea. The AHI after VNS treatment remained <5 in the majority of patients and was only mildly elevated (<12) in five patients. In one patient, CPAP resolved VNS-related respiratory events.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66447/1/j.1528-1157.2003.56202.x.pd
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