title: Policy reform and labour demand in branches of Sri Lankan manufacturing industry

authors: Gibson, John

subjects: Sri Lankan manufacturing industry

abstract: Many policy reforms in developing countries aim to remove factor market distortions. Whether such reforms reduce unemployment depends partly on the substitution possibilities between labour and other factors of production. This paper examines labour demand in seven branches of Sri Lankan manufacturing industry, using data on 4-digit industrial categories over the 1990 to 1997 period. The Box-Cox transformation is used to allow for flexible, and data-dependent, elasticities. The elasticity of capital-labour substitution varies widely across the branches of industry and is usually variable rather than constant. The average, long-run own-wage elasticity of labour demand for the manufacturing sector is estimated as -0.80, so factor price policy should have an important effect on labour demand in this setting.

text: Policy reform and labour demand in branches of Sri Lankan manufacturing industry Many policy reforms in developing countries aim to remove factor market distortions. Whether such reforms reduce unemployment depends partly on the substitution possibilities between labour and other factors of production. This paper examines labour demand in seven branches of Sri Lankan manufacturing industry, using data on 4-digit industrial categories over the 1990 to 1997 period. The Box-Cox transformation is used to allow for flexible, and data-dependent, elasticities. The elasticity of capital-labour substitution varies widely across the branches of industry and is usually variable rather than constant. The average, long-run own-wage elasticity of labour demand for the manufacturing sector is estimated as -0.80, so factor price policy should have an important effect on labour demand in this setting.

year: 2006

title: Further studies on the dialkylation chemistry of [Pt₂(μ-S)₂(PPh₃)₄] with activated alkyl halides RC(O)CH₂X (X = Cl, Br)

authors: Ujam, Oguejiofo Theophilus

subjects: Dinuclear platinum complexes

abstract: Further studies have been carried out into the reactivity of [Pt₂(μ-S)₂(PPh₃)₄] towards a range of activated alkylating agents of the type RC(O)CH₂X (R = organic moiety e.g. phenyl, pyrenyl; X = Cl, Br). Alkylation of both sulfide centres is observed for PhC(O)CH₂Br, 3-(bromoacetyl)coumarin [CouC(O)CH₂Br], and 1-(bromoacetyl)pyrene [PyrC(O)CH2Br], giving dications [Pt₂{μ-SCH₂C(O)R}₂ (PPh₃)₄] ²⁺, isolated as their PF₆⁻ salts. The X-ray structure of [Pt₂{μ-SCH₂C(O)Ph}₂ (PPh₃)₄](PF₆) ₂ shows the presence of short Pt•••O contacts. In contrast, the corresponding chloro compounds [typified by PhC(O)CH₂Cl] and imino analogues [e.g. PhC(NOH)CH₂Br] do not dialkylate [Pt₂ (μ-S)₂(PPh₃)₄]. The ability of PhC(O)CH₂Br to dialkylate [Pt₂(μ-S)₂(PPh₃)₄] allows the synthesis of new mixed-alkyl dithiolate derivatives of the type [Pt₂{μ-SCH₂C(O)Ph}(μ-SR)(PPh₃)₄]²⁺ (R = Et or n-Bu), through alkylation of in situ-generated monoalkylated compounds [Pt₂(μ-S)(μ-SR)(PPh₃)₄]⁺ (from [Pt₂(μ-S)₂(PPh₃)₄] and excess RBr). In these heterodialkylated systems ligand replacement of PPh₃ occurs by the bromide ions in the reaction mixture forming monocations [Pt₂{μ-SCH₂C(O)Ph}(μ-SR)(PPh₃)₃Br]⁺. This ligand substitution can be easily suppressed by addition of PPh₃ to the reaction mixture. The complex [Pt₂{μ-SCH₂C(O)Ph}(μ-SBu)(PPh₃)₄]²⁺ was crystallographically characterised. X-ray crystal structures of the bromide-containing complexes [Pt₂{μ-SCH₂C(O)Ph}(μ-SR)(PPh₃)₃Br]+ (R = Et, Bu) are also reported. In both structures the coordinated bromide is trans to the SCH₂C(O)Ph ligand, which adopts an axial position, while the ethyl and butyl substituents adopt equatorial positions, in contrast to the structures of the dialkylated complexes [Pt₂{μ-SCH₂C(O)Ph}₂(PPh₃)₄]²⁺ and [Pt₂{μ-SCH₂C(O)Ph}(μ-SBu)(PPh₃)₄]²⁺ (and many other known analogues) where both alkyl groups adopt axial positions.

text: Further studies on the dialkylation chemistry of [Pt₂(μ-S)₂(PPh₃)₄] with activated alkyl halides RC(O)CH₂X (X = Cl, Br) Further studies have been carried out into the reactivity of [Pt₂(μ-S)₂(PPh₃)₄] towards a range of activated alkylating agents of the type RC(O)CH₂X (R = organic moiety e.g. phenyl, pyrenyl; X = Cl, Br). Alkylation of both sulfide centres is observed for PhC(O)CH₂Br, 3-(bromoacetyl)coumarin [CouC(O)CH₂Br], and 1-(bromoacetyl)pyrene [PyrC(O)CH2Br], giving dications [Pt₂{μ-SCH₂C(O)R}₂ (PPh₃)₄] ²⁺, isolated as their PF₆⁻ salts. The X-ray structure of [Pt₂{μ-SCH₂C(O)Ph}₂ (PPh₃)₄](PF₆) ₂ shows the presence of short Pt•••O contacts. In contrast, the corresponding chloro compounds [typified by PhC(O)CH₂Cl] and imino analogues [e.g. PhC(NOH)CH₂Br] do not dialkylate [Pt₂ (μ-S)₂(PPh₃)₄]. The ability of PhC(O)CH₂Br to dialkylate [Pt₂(μ-S)₂(PPh₃)₄] allows the synthesis of new mixed-alkyl dithiolate derivatives of the type [Pt₂{μ-SCH₂C(O)Ph}(μ-SR)(PPh₃)₄]²⁺ (R = Et or n-Bu), through alkylation of in situ-generated monoalkylated compounds [Pt₂(μ-S)(μ-SR)(PPh₃)₄]⁺ (from [Pt₂(μ-S)₂(PPh₃)₄] and excess RBr). In these heterodialkylated systems ligand replacement of PPh₃ occurs by the bromide ions in the reaction mixture forming monocations [Pt₂{μ-SCH₂C(O)Ph}(μ-SR)(PPh₃)₃Br]⁺. This ligand substitution can be easily suppressed by addition of PPh₃ to the reaction mixture. The complex [Pt₂{μ-SCH₂C(O)Ph}(μ-SBu)(PPh₃)₄]²⁺ was crystallographically characterised. X-ray crystal structures of the bromide-containing complexes [Pt₂{μ-SCH₂C(O)Ph}(μ-SR)(PPh₃)₃Br]+ (R = Et, Bu) are also reported. In both structures the coordinated bromide is trans to the SCH₂C(O)Ph ligand, which adopts an axial position, while the ethyl and butyl substituents adopt equatorial positions, in contrast to the structures of the dialkylated complexes [Pt₂{μ-SCH₂C(O)Ph}₂(PPh₃)₄]²⁺ and [Pt₂{μ-SCH₂C(O)Ph}(μ-SBu)(PPh₃)₄]²⁺ (and many other known analogues) where both alkyl groups adopt axial positions.

year: 2011

title: Boat electrofishing survey of fish abundance in the Ohau Channel, Rotorua, in 2017

authors: Hicks, Brendan J.

abstract: The aim of the survey was to provide on-going monitoring of the fish communities and abundance by boat electrofishing in the Ohau Channel, especially fish species that are taonga to Maori (tuna, or eels, morihana, or goldfish, and kōura, or freshwater crayfish). In the current study, we present the findings from the eleventh year of sampling (2017) and a summary of previous surveys.
We used the University of Waikato’s 4.5 m-long, aluminium-hulled electrofishing boat to catch a total of 1,110 fish and 3 kōura (18.2 kg in total) from 11 sites on 5 December 2017. The sites comprised 2,909 lineal m and 11,636 m2 in area. Kōura (freshwater crayfish) and 6 fish species were present, with common bully the most abundant species (up to 29.6 fish 100 m⁻² at the site 8, edge habitat). Goldfish (up to 14.2 100 m⁻²) was the next most abundant species, with most goldfish at sites 8 and 11 in and around the side channel. Common smelt were next the most abundant species (up to 11.4 fish 100 m⁻²). Mean density of bullies (7.8 fish 100 m⁻²) was much higher than for smelt (1.69 fish 100 m⁻²). Kōura had a patchy distribution with only 3 individuals were caught at two sites.
Comparing catches over the 11 years of sampling, the mean abundance of common bullies in 2017 was consistent with densities in most post-wall years (after 2007), but lower than in 2007 before wall closure (Newman-Keuls multiple range test, P = 0.034). The cause of fluctuating bully abundance is not known, and was not accounted for by changes in water clarity expressed as black disc distance (BDD), water temperature, or water conductivity. Poor water clarity can reduce the efficiency of electrofishing, but low BDD did not correspond with low common bully densities. In 2017, smelt abundance had recovered somewhat from the low catches from 2014 to 2016.
Goldfish biomass increased initially (2009-2010) because of targeted fishing in the side channel (site 11), which has dense macrophytes and offers good habitat for goldfish with no flow. However, the continued rise in goldfish density from 2012 on suggests a real increase in goldfish numbers. In contrast to most previous years, no eels were caught in 2017.
Analysis of fish densities before and after wall closure is hampered by the single data point before closure. However, we now have 10 years of post-wall data, and comparisons of means and standard deviations suggest that the number of bullies have been lower since 2008 with the exception of 2015, when bully densities were the same as 2007, i.e., before wall closure. The large number of small juvenile bullies (<30 mm) suggests that recruitment is taking place in the channel, so fluctuating bully abundance is likely to be controlled by factors other than wall closure.

text: Boat electrofishing survey of fish abundance in the Ohau Channel, Rotorua, in 2017 The aim of the survey was to provide on-going monitoring of the fish communities and abundance by boat electrofishing in the Ohau Channel, especially fish species that are taonga to Maori (tuna, or eels, morihana, or goldfish, and kōura, or freshwater crayfish). In the current study, we present the findings from the eleventh year of sampling (2017) and a summary of previous surveys.
We used the University of Waikato’s 4.5 m-long, aluminium-hulled electrofishing boat to catch a total of 1,110 fish and 3 kōura (18.2 kg in total) from 11 sites on 5 December 2017. The sites comprised 2,909 lineal m and 11,636 m2 in area. Kōura (freshwater crayfish) and 6 fish species were present, with common bully the most abundant species (up to 29.6 fish 100 m⁻² at the site 8, edge habitat). Goldfish (up to 14.2 100 m⁻²) was the next most abundant species, with most goldfish at sites 8 and 11 in and around the side channel. Common smelt were next the most abundant species (up to 11.4 fish 100 m⁻²). Mean density of bullies (7.8 fish 100 m⁻²) was much higher than for smelt (1.69 fish 100 m⁻²). Kōura had a patchy distribution with only 3 individuals were caught at two sites.
Comparing catches over the 11 years of sampling, the mean abundance of common bullies in 2017 was consistent with densities in most post-wall years (after 2007), but lower than in 2007 before wall closure (Newman-Keuls multiple range test, P = 0.034). The cause of fluctuating bully abundance is not known, and was not accounted for by changes in water clarity expressed as black disc distance (BDD), water temperature, or water conductivity. Poor water clarity can reduce the efficiency of electrofishing, but low BDD did not correspond with low common bully densities. In 2017, smelt abundance had recovered somewhat from the low catches from 2014 to 2016.
Goldfish biomass increased initially (2009-2010) because of targeted fishing in the side channel (site 11), which has dense macrophytes and offers good habitat for goldfish with no flow. However, the continued rise in goldfish density from 2012 on suggests a real increase in goldfish numbers. In contrast to most previous years, no eels were caught in 2017.
Analysis of fish densities before and after wall closure is hampered by the single data point before closure. However, we now have 10 years of post-wall data, and comparisons of means and standard deviations suggest that the number of bullies have been lower since 2008 with the exception of 2015, when bully densities were the same as 2007, i.e., before wall closure. The large number of small juvenile bullies (<30 mm) suggests that recruitment is taking place in the channel, so fluctuating bully abundance is likely to be controlled by factors other than wall closure.

year: 2018