The toxicity of ammonia to fishes has been attributed to the un-ionized ammonia chemical species present in aqueous solution. Because the percent of total ammonia present as un-ionized ammonia (NH3) is so dependent upon pH and temperature, an exact understanding of the aqueous ammonia equilibrium is important for toxicity studies. A critical evaluation of the literature data on the ammonia–water equilibrium system has been carried out. Results of calculations of values of pKa at different temperatures and of percent of NH3 in aqueous ammonia solutions of zero salinity as a function of pH and temperature are presented.

In the normal newborn rat the retinotectal pathway from each eye distributes across the whole area of both the ipsilateral and contralateral superior colliculus. Most of the ipsilateral projection retracts during the first ten postnatal days to produce the normal adult pattern, but retraction fails to occur if one eye is removed at birth.

The complexity of current disasters creates a challenge for crisis communication. This paper aims at identifying gaps in communication in disaster management experienced in practice in order to facilitate learning from those situations. The research was conducted using a qualitative online open‐ended questionnaire. It shows that despite the developments in the discipline, communication as an integral part of decision making in disaster management needs to be further developed. The paper provides a practical‐oriented overview of the communication constraints in complex crisis situations, which has not been provided so far. This research is part of an international project developing performance indicators for a quality measurement system for crisis communication.

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BackgroundThe paper explores how age, social position or class, and linguistic and cultural background intersect and place women in varying positions of control and vulnerability to obstetric violence in state health institutions in Colombo district, Sri Lanka. Obstetric violence occurs during pregnancy, childbirth and the immediate postpartum period; hence, it is violence that directly affects women. The authors aim to break the traditional culture of silence around obstetric violence and bring attention to the resulting implications for quality of care and patient trust in obstetric care facilities or providers.MethodsFive focus group discussions were held with 28 public health midwives who had prior experience working in labor rooms. Six focus group discussions were held with 38 pregnant women with previous childbirth experience. Additionally, 10 of the 38 women, whom felt they had experienced excessive pain, fear, humiliation, and/or loss of dignity as patients in labor, participated in individual in-depth interviews. An intersectional framework was used to group the qualitative data into categories and themes for analysis.ResultsObstetric violence appears to intersect with systems of power and oppression linked to structural gender, social, linguistic and cultural inequities in Sri Lanka. In our dataset, younger women, poorer women, and women who did not speak Sinhala seemed to experience more obstetric violence than those with relevant social connections and better economic positions. The women in our study rarely reported obstetric violence to legal or institutional authorities, nor within their informal social support networks. Instead, they sought obstetric care, particularly for childbirth, in other state hospitals in subsequent pregnancies.ConclusionsThe quality of obstetric care in Sri Lanka needs improvement. Amongst other initiatives, policies and practices are required to sensitize health providers about the existence of obstetric violence, and repercussions are required for abusive or discriminatory practices. The ethics of care should be further reinforced in the professional training of obstetric health providers.

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Horseradish peroxidase was injected into the superior colliculus of normal pigmented and albino rats and rats which had been unilaterally enucleated at birth, in order to identify the retinal ganglion cells which contribute normal and abnormal uncrossed retinotectal axons. The results show that while in pigmented rats, the normal uncrossed pathway derives solely from the lower temporal retina and distributes to the anterior and medial parts of the colliculus, occasional cells throughout the retina of albino rats contribute to the uncrossed pathway and the terminal distribution is broader in the tectum. These findings are confirmed with orthograde pathway tracing methods. After neonatal unilateral eye enucleation, many more ganglion cells in the remaining eye of both pigmented and albino rats project ipsilaterally. It is notable from both HRP studies and from further degeneration experiments that cells in part of the lower temporal retina do not restrict their distribution to a mirror togographic position in the ipsilateral tectum but send axons across all but the posterolateral part of the colliculus. No single class of ganglion cell (defined by soma diameter) appears responsible for the expanded ipsilateral projection, although more large cells from the lower temporal retina are involved. These may be the result of enlargement of cells with expanded terminal fields rather than necessarily indicating a preferential contribution from one retinal ganglion cell class.

Slums are universally assumed to be the worst places for people to live in, and it is often taken for granted that the livelihood situations of slum communities are also uniform and homogenous. So pervasive is the latter idea that most studies examining the livelihood situations of slum communities do not compare the socio-economic and cultural differences within such communities. A distinctive feature of slum communities is the pursuance of multiple livelihood strategies that are tied to migration. However, the links between migration and livelihood situations in many slum communities have not been extensively examined. The article seeks to examine the many faces of Nima, a slum community in Accra (Ghana), and link these to livelihoods and migration. The data for the study are drawn from varied sources, including in-depth, key informant interviews, personal observations, and census reports. The complexity and varied migration patterns both internationally and internally tied to livelihoods in Nima are revealed. The changing character of slums is discussed and it is concluded that slums are not only a matter of the negative aspects of urban places but there are positive sides as well. The significance of migration and migrants is crucial for understanding Nima's role in urban development, and for making the appropriate recommendations for livelihoods development in Nima.