Diversity of moths from the urban set-up of Valmiki Nagar, Chennai, India

A study was conducted at Valmiki Nagar, Chennai, Tamil Nadu, India to explore its moth diversity from December 2018 to May 2021. This manuscript presents a partial checklist of moths from Valmiki Nagar. Four locations around the colony were studied to record the moth fauna. The study sites were surveyed twice a month using a mercury vapour lamp along with a white sheet, along with over 100 visits at night. Diurnal surveys were conducted bimonthly to observe larval host plants and day flying moths. A total of 135 species were recorded from the study area, belonging to nine superfamilies. The most diverse family of moths recorded was family Erebidae, with 39% of moths recorded in the study belonging to this family, followed by Crambidae (30%), Geometridae (8%), and other families constituting the rest. The moth diversity in the month of July was seen to be the highest. Along with this study, future studies on similar lines will help in documenting the moth diversity of Chennai.

Photodegradation Properties of Earlywood and Latewood Spruce Timber Surfaces

Spruce (Picea abies Karst.) samples were irradiated using an ultraviolet light emitter mercury vapour lamp. The examined specimen surfaces contained earlywood or latewood to determine the photodegradation properties of these two tissue types. The generated chemical changes were monitored by diffuse reflectance Fourier transformed infrared spectroscopy. The difference spectrum method was used to present absorption changes. The earlywood suffered considerably greater degradation than the latewood during the UV irradiation. Most of the lignin molecules in the examined surface layer degraded during the first 11 days of UV irradiation for both earlywood and latewood. Results demonstrated that two types of unconjugated carbonyls absorbing at 1705 and 1764 cm–1 wavenumbers were created during the photodegradation. Time dependence of the absorption changes showed correlation between the guaiacyl lignin degradation and the generation of unconjugated carbonyl group absorbing at 1764 cm–1 wavenumber.

Testing the Photostability of Acetylated and Boiled Linseed Oil-coated Common Hornbeam (Carpinus betulus L.) Wood

In this study, the effect of acetylation and coating with boiled linseed oil was evaluated concerning the photodegradation of common hornbeam wood (Carpinus betulusL.). To measure colour stability, a 10-month-long outdoor weather resistance test without soil contact was performed as well as artificial aging using a 200 hour mercury-vapour lamp irradiation test. The measurements were done on hornbeam, acetylated hornbeam, boiled linseed oil-treated hornbeam, and acetylated and boiled linseed oil-treated hornbeam samples. The control and treated samples’ colour change was determined by comparing them to the original colour in all cases. The photodegradation process was examined with Fourier Transform Infrared (FTIR) spectra. Acetylated hornbeam was less prone to crack, but the modification did not hinder the fading and greying caused by UV irradiation. Coating the samples with boiled linseed oil decreased the rate of colour change and cracking. The photodegradation of lignin was confirmed by the FTIR spectra.

Photodegradation of Timber of Three Hardwood Species Caused by Different Light Sources

- In this study, resistance of black locust, beech and poplar wood to photodegradation was tested, applying sunlight, a xenon lamp and a mercury vapour lamp. The irradiation time was 200 hours for sunlight and the xenon light and 20 hours for the mercury light. The changes were monitored by colour measurements and infrared spectroscopy. The colour change of black locust was more intensive at the beginning of the irradiation than that of the beech and poplar. The degradation of aromatic structure of lignin (absorbing at 1510 and 1596 cm-1) in black locust was minor compared to the same changes of beech and poplar during the first 10 hours. The mercury lamp induced more intensive changes both in colour and in infrared spectrum than the other two light sources. The results show that the high extractive content of black locust absorbs a considerable amount of light radiation protecting the main chemical components of wood.

Comparative effectiveness of UV wavelengths for the inactivation of Cryptosporidium parvum oocysts in water

Cryptosporidium parvum oocysts in water were exposed to distinct wavelength bands of collimated beam ultraviolet (UV) radiation across the germicidal UV wavelength range (210-295 nm) that were emitted from a medium pressure (MP) mercury vapour lamp. The dose of UV radiation transmitted though each narrow bandpass filter was measured utilising potassium ferrioxalate actinometry. Oocyst infectivity was determined using a cell culture assay and titre was expressed as an MPN. The log10 inactivation for each band of radiation was determined for a dose of 2 mJ/cm2. Doses from all wavelengths between 250-275 nm resulted in approximately 2 log10 inactivation of Cryptosporidium parvum oocyst infectivity while doses with wavelengths higher and lower than this range were less effective. Because polychromatic radiation from MP UV lamps had about the same germicidal activity between the wavelengths of 250-275 nm for inactivation of oocyst infectivity, there was no unique advantage of MP UV over low pressure (LP) UV except for the simultaneous delivery of a wide range of germicidal wavelengths.

Intercalibration of different light-traps and bulbs used in moth monitoring in northern Europe

Four different combinations of light-traps and bulbs were tested during the summer 1996 in Kainuu, northern Finland: a Jalas model with a 160-W (J/160W) blended light lamp or a 125-W (J/125W) mercury vapour lamp, a Ryrholm trap with a 125-W (R/125W) mercury vapour lamp and a Rothamsted trap with a 200-W tungsten lamp (G/200W). The traps were rotated between four sites every night, but were kept in the same position for the fifth night in order to prevent the possible influence of moonlight. The longest distance between the traps was 150m, and there was no direct visibility between any of them. Three orders were inspected, i.e. Lepidoptera, Coleoptera and Hemiptera, the total numbers of individuals and species being as follows: 20857/425, 862/101 and 1868/58. G/200W collected significantly fewer moths than the other traps. In some cases, J/125W collected significantly more moths and less species than the J/160W design. The R/125W design collected significantly more species than the J/160W design. Similar differences in the effectiveness of the lamps and traps were found in the case of Coleoptera and Hemiptera. Alpha diversities showed the same trend.

Photochemical nucleophile–olefin combination, aromatic substitution (photo-NOCAS) reaction. Part 7: methanol, conjugated dienes, and 1,4-dicyanobenzene

The scope of the photochemical nucleophile–olefin combination, aromatic substitution (photo-NOCAS) reaction has been extended to include conjugated dienes: 1,3-butadiene (9), 2-methyl-1,3-butadiene (10), 2,3-dimethyl-1,3-butadiene (11), and 2,5-dimethyl-2,4-hexadiene (12). Acetonitrile–methanol solutions of the dienes 9,10, and 11, and 1,4-dicyanobenzene (1), with and without codonor (biphenyl (5)), were irradiated with a medium-pressure mercury vapour lamp through Pyrex. Both 1,2- and 1,4-addition products were formed in approximately equal amounts (combined yields of photo-NOCAS products, 50–65%). In marked contrast, when an acetonitrile–methanol solution of 2,5-dimethyl-2,4-hexadiene (12), 1, and 5 was irradiated, only the 1,4-addition product, trans-2-(4-cyanophenyl)-5-methoxy-2,5-dimethyl-3-hexene (22,82%), was obtained. This photolysate also contained a small amount of another 1,4-addition product, that which had incorporated cyanide ion instead of methanol, trans-2-(4-cyanophenyl)-2,2,5-trimethyl-3-hexenenitrile (23, 2%). Irradiation of an acetonitrile solution (no methanol) of 12,1, and 5 gave 23 in good yield (68%). An excellent yield (80%) of 23 was obtained upon irradiation of an acetonitrile solution of 1,12, 5, potassium cyanide, and 18-crown-6. Addition of 2,4,6-trimethylpyridine (collidine, 25), a mild, non-nucleophilic base, to the reaction mixture diverts the reaction involving 12 from photo-NOCAS products to 1:1 substitution products; 3-(4-cyanophe-nyl)-2,5-dimethyl-1,4-hexadiene (26), trans-5-(4-cyanophenyl)-2,5-dimethyl-1,3-hexadiene (27), (Z)-1-(4-cyanophenyl)-2,5-dimethyl-2,4-hexadiene (28), and (E)-1-(4-cyanophenyl-2,5-dimethyl-2,4-hexadiene (29) were formed. The mechanisms of these reactions are discussed and an explanation for the observed regio- and stereoselectivity is given.

1,n-Radical ions. Photosensitized (electron transfer) carbon–carbon bond cleavage. Formation of 1,6-radical cations

The reactivity of the radical cations of methyl 2,2-diphenylcyclohexyl ether (7), 6,6-diphenyl-1,4-dioxaspiro[4.5]decane (8), methyl cis- and trans-2-phenylcyclohexyl ether (9cis and trans), and 6-phenyl-1,4-dioxaspiro[4.5]decane (10), generated by photosensitized (electron transfer) irradiation, has been studied. Solutions of the ethers and acetals in acetonitrile–methanol (3:1), with 1,4-dicyanobenzene (2) serving as the electron acceptor, were irradiated with a medium-pressure mercury vapour lamp through Pyrex. The diphenyl derivatives 7 and 8 were reactive; 7 gave 6,6-diphenylhexanal dimethyl acetal (11) and 8 gave 2-methoxy-2-(5,5-diphenylpentyl)-1,3-dioxolane (12). These are the products expected from the intermediate 1,6-radical cation, formed upon carbon–carbon bond cleavage of the cyclic radical cation. The monophenyl derivatives 9cis and trans and 10 were stable under these irradiation conditions. The mechanism for the carbon–carbon bond cleavage and for the cis–trans isomerization is discussed. An explanation, based upon conformation, is offered for the lack of reactivity of 9 and 10. Molecular mechanics (MM2) calculations were used to determine the preferred conformation of 9cis and trans, and 10. Key words: photosensitization, electron transfer, radical cation, carbon–carbon bond cleavage, conformation.

Hydrophobic binding domains of rat intestinal maltase–glucoamylase

Rat intestinal microvillus maltase–glucoamylase was isolated by detergent extraction and purification in the presence of protease inhibitors as previously described and incorporated into phospholipid vesicles. After purification of the vesicles on Scphadex G-50, maltase was labelled with 3-trifluoromethyl-3-(m-[125I]iodophenyl) diazirine ([125I]T1D) by photolysis using a water-jacketed mercury vapour lamp with a saturated CuSO4 filter. The labelled enzyme was extracted with acetone, resuspended in 1% Triton X-100, reincorporated into phospholipid vesicles, and digested with activated papain to release the hydrophilic polar head of the enzyme from the vesicle bilayer. Vesicle-bound and free enzyme components were separated on Scpharose 4B. Ninety percent of the enzymatic activity was free, while a similar percentage of radioactive label remained with the vesicles in keeping with the separation of an active polar headpiece from a labelled apolar peptide in the lipid bilayer. The vesicle fractions were subjected to chromatography on Sephadex LH-60 with cthanol – formic acid (7:3) as the eluant. A single radioactive peak (14 kilodaltons (kDa)) was separated from labelled lipid. Sodium dodecyl sulfate – polyacrylamide gel electrophoresis of the peak showed a radioactive doublet of 26–28 kDa, possibly representing a dimer. No other labelled peptides were found. These results suggest that detergent-solubilized maltase–glucoamylase is inserted into the phospholipid bilayer via an apolar peptide with a minimum molecular mass of 14 kDa. The peptide probably represents a terminal anchor segment of the 145-kDa subunit which is converted to 130 kDa when the membrane-bound enzyme is solubilized by papain.